Tag Archives: Top-Grade Ammo

RELOADERS CORNER: Seating Depth Issues

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Don’t take anything for granted! Safety and suitability are both at risk if you don’t take time to analyze and act on this important topic. READ MORE

land illustration

Glen Zediker

As said often, it’s sometimes recent experience that leads to my Reloaders Corner topics. Whether it’s a question I’ve been asked, usually, or, in this case, a malfunction I’ve had, those things are fresh in my mind. I hope to believe, and have to believe, that any such topics aren’t only a question for them, or for me.

That brings us to bullet seating depths, which really means overall cartridge length, using some particular bullet.

Usually, when we’re loading for a rifle with a box magazine, either bolt-action or semi-auto, the cartridge overall length — that’s measured from the base of the case to the tip of the bullet — defines and determines the maximum length. Usually.

What ultimately determines the cartridge overall length maximum, though, is really the first point of contact that the bullet makes (will make) with the rifling or lands ahead of the chamber throat. That space, and therefore overall round length, has a whopping lot to do with the chamber reamer specs, and also the reamer operator’s judgment in some cases, but we need to know.

It also can have a whopping lot to do with the bullet! And that’s what the most of this next is all about.

So here’s the lesson to learn, and, for me, to relearn: Do not assume that if the round fits into the magazine it will be fine. I will, at the least, freely admit to my mistakes because, one, I dang sho should know better, and, two, if I know better and still don’t do better confession is my punishment. Well, not really, but it’s always a wake-up call.

Different bullets have different profiles, different ogive architectures. The ogive is the “curve” beyond the last point up the bullet that’s caliber diameter (meaning full diameter) ending at the bullet tip. My slang but descriptive term for this is “nosecone.” Tracing up this curve, some point will be equal to land diameter. So where this point is on the seated bullet and where this point is ahead of it in the chamber matters a lot.

Unless it’s done as a deliberate tactic, there needs to be some space, some distance between the land diameter point on the bullet nosecone and the lands. The amount of that distance is referred to as “jump,” because that’s descriptive. It’s the gap the bullet has to cross through to engage into the rifling. Usually the closer the better, and that “tactic” used often by precision shooters (mostly long-range and Benchrest competitors) is to purposely seat the bullet so it’s touching the lands. That’s done in the belief that if there’s no jump, then there’s no ill effects from jump. It’s very often right, and I’ve proven that to myself many a time. It’s not always right, but then if it was this all would be too easy.

The reason there needs to be some space is because when a bullet goes from just off to just on the lands, pressure jumps. It’s a “spike,” not a surge, but it’s enough to put a load that’s nearing the edge over the edge. In something like a .223 Rem. it’s about a half-grain-worth of propellant.

hornady 52
Here’s one I messed up with. The ogive or nosecone profile on this bullet is much “higher” than normal for a match bullet of this weight and it encountered the lands at a much shorter overall length than any others I had used. I learned the hard way, even though I already knew better.

So. Here’s the lesson I learned again, but this one wasn’t my fault! Honest! Several years ago, however, here’s one that was my fault: new (to me) match bullet, a short 52-gr. I wanted to try for reduced-course NRA High Power Rifle events. Rifle had a Wylde .223 Rem. chamber. A Wylde has a throat length between a 5.56 NATO and a SAAMI-spec. .223 Rem. That means the throat is fairly much more generous than commercial .223 Rem. specs. The maximum cartridge overall length in an AR15 box magazine is 2.260 inches, and I go 2.255 for a margin. I checked some industry manual data for this bullet and did notice that the overall cartridge length listed in the data spec table was a good deal shorter than that. I quickly did some “math” but without numbers (so it wasn’t really math) and decided that since I had a longer chamber I’d ignore that and just seat the bullets to 2.255. Blew primers right and left.

Back home and gage in hand and, dang, they weren’t kidding! I was about 0.020 into the lands at that cartridge length. That’s a honking lot. That’s also ultimately dangerous because of the free-floating firing pin tapping off the primer when a round is loaded into an AR15. A bullet that’s getting jammed into the lands is greatly more resistant to chambering freely and fully.

I humbly learned my lesson.

Get a gage and use it! The best out there is the Hornady LNL Overall Length gage. This tool lets you very easily find the overall round length that touches the lands with your bullet in your barrel. Very valuable, that.

lnl oal gages
A Hornady LNL OAL Gage will show right quick like and in a hurry with the seating depth that touches the lands is with your bullet in your gun. Valuable!

Use it in conjunction with its companion “bullet length comparator” insert for the very best precision. That tool measures a bullet at a point on its ogive that (usually) corresponds closely with land diameter. It won’t be perfectly the same, but it doesn’t have to be. What matters is that it gives a more accurate figure. Avoiding the bullet tip in a measurement eliminates that (guaranteed, by the way) inconsistency in accurate measurement because of bullet tip variations.

LNL comparator
A “comparator,” like this one from Hornady’s LNL line, is a much more accurate way to measure seating depth because the bullet tip doesn’t get involved. I like the curved one: easier and more accurate by my experience.

Now. To the recent experience: It was with a .300 Blackout (AAC) subsonic. I did not have the means to gauge this using my tools (then, but I do now). However, that wouldn’t have mattered in this case, and why is next.

Tested a factory load. Liked it. Noticed nothing unusual. Functioned perfectly, shot well. Brought it home and filled a magazine, loaded one in the chamber, and set it aside. Folks, just so you don’t think I’m irresponsible, that gun is what I keep at the ready for home-defense. So, my son, who had gone in to unload and then dry-fire the gun, came up and said, “Dad. The bolt won’t open.” Dang. It wouldn’t. I started thinking up all reasons that might be behind that. The bolt carrier would retract a little way, which was the limit of usual “play” in the bolt travel inside it, so I didn’t think anything was broken. To remove the round I pulled off the upper, took it to the shop, and pried back the bolt carrier from the underside. A couple of careful but firm enough strokes and it opened.

The bullet had really jammed into the lands! I mean really jammed. Extracting the round and looking at it, land impressions were clear, and measuring the extracted round showed it was 0.022 longer than the new, un-chambered round. Unseating the jammed round pulled the bullet that far out from the case neck.

I manually inserted another round of the same into the chamber and gave it a nudge-in with my finger, and, sure enough, there it sat not nearly fully into the chamber. Had to tap it back out.

jammed bullet
Here’s the “stuck” round, right, talked over in the article. Land impression is pretty clear, and pretty deep. Notice also that the bullet got pulled out a might upon finally opening the action. On left is the same round out of the same box that was pushed into the chamber; land marks also, just a lot lower!

So. Since it’s a factory load, I really couldn’t have had a clue that it wasn’t compatible with my chamber throat. But now I do. And, for a clue, do that same yourself. If the round won’t drop in and out of a chamber fully and easily, that might be a problem. I still don’t know what the actual measured amount of the excessive length might have been. To find that I’d have to get a box of those bullets and gauge them using the LNL tools. I’m not going to do that. I’ve chosen another load that’s no-issues.

I say “might be” because, again these rounds functioned well, but, also, well, that can’t be good…

I suppose I will now need to start handloading for that contraption. I have also written down 100 times: “I will always check the chamber throat, even if it’s not a long-range rifle…”

Find gages at Midsouth HERE and HERE

The preceding is a specially-adapted excerpt from Glen’s book Top-Grade Ammo. Available HERE at Midsouth Shooters Supply. Visit ZedikerPublishing.com for more information on the book itself, and also free article downloads.

RELOADERS CORNER: Case Trimmers

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An ideal case trimmer provides precision, speed, and affordability. Here are some ideas on avoiding compromise. READ MORE

Hornady Cam-Lok
Hornady Cam-Lock. Good trimmer at a fair price. See it HERE

Glen Zediker

At some point, or points, cases need to be trimmed to a shorter length. Brass flows. Therefore, a case trimmer is pretty much a given in the tool assortment for any handloader.

There are needs and wants, realities and ideals. That’s true with many things, and applies often to reloading equipment. Ideally, a case trimmer will go beyond just trimming the case to a shorter length. They all do that well enough. I think it’s important that a case has a square mouth — dead flat across the top. This is an asset to getting a bullet started well into the case neck during the seating operation.

A Good Trimmer
There are a variety of trimmers available from most of the popular industry tooling suppliers. And most follow a pretty similar form and formula: a little hand-cranked lathe. In these, the back end of the case is chucked into a collet-type fitting. A caliber-size pilot that’s centered in and surrounded by a cutting head goes into the case neck and supports the front of the case.

Not nearly perfect! There are a few reasons and sources for reduced precision. The tool alignment may be true at each “end” of the trimmer, but the case we’re working with probably isn’t true. Mostly, since there has to be a gap for the pilot to freely rotate, and since case neck walls aren’t all consistent in thickness, the fit isn’t close enough to prevent out-of-round rotation. Along with the inevitable case body warp there’s bound to be a tad amount of wiggle. Since the case is supported only at its head area, not by its body, there’s flex afoot.

None of that means the case neck won’t get trimmed to a shorter length, which is the general idea. It does, however, mean that it’s not liable to be perfectly squared up.

LE Wilson
LE Wilson. See it HERE at Midsouth.

A Better Trimmer
I rarely just overtly recommend one tool over all the others, but after a good many years working with case trimmers, I can and will tell you that the LE Wilson design is the best I’ve yet tried. I guess, yes, that is just opinion, but it’s really not.

The difference in this trimmer design is that the case is supported within a sleeve by its body. There’s no polarized suspension front and back. Mostly, there’s no pilot. The cutter on an LE Wilson faces off the front of the case squarely. The sleeve holding the case sit atop a pair of rails and the whole arrangement excludes case condition from the process.

le wilson sleeve
Tap it in… Then tap it out…

le wilson sleeve

So why doesn’t everyone use one? Honestly, I’m not entirely sure. It is a different arrangement, and it’s not cheap, especially not if you accessorize the fool out of it with a stand, a clamping device, and a micrometer. It’s not more than the other higher-end manual trimmers though.

It’s also fast! There’s no clamp-twisting to get the next case in place, and back out again. The sleeves are slightly tapered inside so the case is tapped in and then tapped out. With a little experience it’s amazingly quick to get through your block full of brass.

Flexibility
Virtually all case trimmers can provide additional utility, do different jobs. The cutter can be replaced with a reamer, and some can get reworked into outside case neck turners.

My choice is usually a stand-alone station, and that’s mostly because it’s pretty tedious refitting the appliances. I am, or at least have become, lazy.

forster case trimmer
Forster. This is a good choice especially for those who want to make a multi-purpose tool out of their base unit. There’s a big collection of add-ons that let work over primer pockets, turn case necks, ream case necks, and even hollow-point bullets. Its precision is better than most.
forster accessories
A a few of the things that can go on a Forster. Very versatile tool!

As with all said about alignment for case length trimming, that is also all the same for using a trimmer for other chores. And, yes, I still think the LE Wilson works best as a reamer, for instance, and that is because all the alignment precision is built into the tool itself; the case doesn’t play a role.

About options, by all means fit up a “combo-head” if it’s available that will finish the trim with a nice inside/outside chamfer/deburr. Big time saver. These can be a trick to get set just right, but it sure saves time.

Power
It sure is nice to get a break from the crank! There are, though, as I see it, two kinds of power case trimmers. Those that replace the hand crank with an electric motor and those that are designed from the start to be powered.

Some trimmers offer a means to add your own power source, like an electric screwdriver or drill.

Gracey Match Prep
Gracey Match Prep. Pretty much a big motor! It’s intimidating on first use, but just push the case in and it gets trimmed (and chamfered). It’s way quick in use and produces precise results.

My favorite proprietary power trimmer is a Gracey “Match Prep.” Designed by the late Doyle Gracey as a fast and easy way to trim huge quantities of Lake City brass for NRA High Power Rilfe shooters, it’s a serious machine. It works like a gigantic electric pencil sharpener, at least in spirit. Pick up a case and push it forward into a collar and it’s trimmed and squarely faced. No clamps or sleeves. The case shoulder stops against the inside of the collar, so it’s imperative that all cases are resized prior to use. As said last time, though, that’s really the only time you’ll get consistent results with any trimmer.

gracey holder
A key to a Gracey’s speed is that the cases stop on the case shoulder: just push it it!

I don’t know how many cases I can trim in an hour because I’ve never spent an hour using a Gracey. I can easily do 100 in under 5 minutes.

Another very good power trimmer is the Giraud. Its essential means for and in operation are about the same as Gracey but it is a nicer package with more features. Gracey is pretty daggone simple. That’s not all bad. I’d say Giraud is the best, and its price does reflect that.

One Last
Again, it’s important to evaluate the overall condition of a batch of cases, related to how many uses they’ve had. Having grown a little longer isn’t likely to be the only thing that’s changed in a case that exceeds whatever limit you set for it.

And, speaking of, the “trim-to” length is usually 0.010 inches shorter than the maximum SAAMI-stated overall case dimension.

Next time we’ll look at tools used to treat the trimmed case necks and finish this task in fine style.

Check out some more options at Midsouth HERE

Gracey
Giraud

The preceding is a specially-adapted excerpt from Glen’s book Top-Grade Ammo. Available HERE at Midsouth Shooters Supply. Visit ZedikerPublishing.com for more information on the book itself, and also free article downloads.

RELOADERS CORNER: Case Trimming

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We all have to trim bottleneck cases sometime. Question is when and how much, and then “how,” and here’s a place to start. KEEP READING

case trimmer

Glen Zediker

After going through that last series on keeping up with changes in cases resulting from their use and reuse, “flow” was a culprit behind the majority of detrimental changes. That is: Brass flows during firing. It moves from where it was to somewhere else. Since there’s a finite amount of material in a case, one place is getting thinner and another is getting thicker. The sources of the material, where the flow starts and where it stops, are primarily case necks and case heads.

To completely finish up on all this, the most obvious indication that there’s flow is measuring case lengths from base to mouth.

case trimming
The primary reason to trim is to keep overly-long cases from overrunning their space in the chamber. If the case mouth encounters the end of its allotted space, it can pinch in on the bullet, elevating pressure. Now, there’s usually a good deal of leeway before safety can be a question, but don’t push it…
measure case length
A caliper is the only tool needed to measure case length. It’s not really necessary to measure each and every case each and every time. It’s a whopping lot faster to set the trimmer so it just touches the shortest case you have (revealed through the process itself in setting up the trimmer) and trim all the cases using that setting locked in place.

First, and very (very) important: The ONLY time to check case length, or to trim cases, is after they have been sized! A fired, unsized case will be shorter than it was going in. The reason is because of the expansion in the case that resulted from firing. When the expanded areas are squeezed back to spec by a sizing die the case gets longer as it gets smaller in diameter, same as rolling a ball of modeling clay out on a table. After sizing is also the only time we can we know that the case shoulder area is consistent in dimension.

You’ll see two length figures published for your cartridge of choice: maximum length and trim-to length. Published trim-to length is usually 0.010-inches under what’s listed as maximum.

I got a gage umpteen years ago that could indicate the maximum case length a chamber could accommodate — technically, a “chamber length gage.” Man. I checked the chambers in my main rifles and found that they were all well more generous than the SAAMI-maximum. That didn’t really mean a lot, in fact, to how I proceeded. And it also didn’t mean I can advise ignoring the potential for danger in exceeding SAAMI-maximum. It just pointed out that there are differences in chambers, gun to gun, and at least showed me that not exceeding max stated length should easily keep you safe.

chamber length gage

If a case got too long, exceeded the amount of room given to it in the chamber, that would be a safety problem! The bolt may not close fully. And, if it did, the extra length would create a pinching-in constriction, and that would spike pressure.

We can easily imagine that there’s an influence from relatively longer or shorter case necks in their influence in consistently encasing the bullet. And I’m sure we’d be right. Trimming cases all the same should mean that all the case neck cylinders are the same height. Someone looking to maximize accuracy is liable to get worked up about that enough to trim each firing. I trimmed my tournament cases each use. And, no, none were remotely approaching maximum length. It’s reasonable to further suppose that more or less retention will influence velocity consistency.

Another performance asset may or may not happen, depending on the trimming tool chosen. But. A good trimmer will square the case mouth. I’ve seen a many new cases with a “half-moon” cut after trimming. A square case mouth helps a bullet start and finish straight when it’s seated.

case trimmer
Not all case trimmers are equal. We’ll talk more about some I like next time, and I’ll tell you why.

My routine for this sort of “accuracy-oriented” case trimming is simple — tedious, but simple. I don’t measure each case. I just run them all through a trimmer set to “some” length. Some are trimmed more or less, some just show a bright scuff on one little bit of the case mouth, but they are then all the same length. If I can’t prove it in group sizes, it sho does set my mind at ease that all the cases are holding all the bullets more nearly the same.

For those rifles that aren’t tournament guns, the only concern is that none, indeed, become too long. Those I will check at that “4-firings-in” point. Some may have reached SAAMI-maximum, most won’t have, but all will be longer than when started. I start them at a figure close to suggested “trim-to.” Stop and think about it, and if there’s been overall a 0.010-inch length increase, that’s significant.

As with all things associated with use and reuse in semi-autos compared to bolt-actions, cases are going to grow more and faster in a gas-gun.

Another instance where it’s important to keep up with case lengths, and that, again, really has to do with making them all the same, is for those who crimp (with a conventional cannelure method).

Now, there’s zero harm in using a longer “trim-to” length, and that may be more popular than my method. These lengths are stated in reloading manuals. Keeping up with it over years, I’ve seen no difference in the rate of lengthening trimming longer or shorter; I trim “shorter” solely as a matter of consistency over the (short) life of my semi-auto cases.

Next time more about the tools.

Get started shopping HERE

The preceding is a specially-adapted excerpt from Glen Zediker’s book Top-Grade Ammo.

Glen’s books, Handloading For Competition and Top-Grade Ammo, are available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

Glen’s newest book, America’s Gun: The Practical AR15. Check it out HERE

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RELOADERS CORNER: 4 Firings In, Part Two

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Cartridge cases always fail on the “next firing.” Question is which one that might be. Need to know! KEEP READING

beat case
I apologize for the image quality, but these were taken a while ago. Fortunately, for me, I didn’t have anything on hand that shows even close to the beating this one took. Cracked neck, head crack. Rare to see one case with both of the most common failures. It was attacked by an M14.

Glen Zediker

I’d always rather say it all at once, but the realities of tolerance, and space, sometimes mean I have to split a bigger topic into smaller installments. The “tolerance” part is how many pages you all are willing to scroll through!

This multi-part topic is when, and then how, to check after the progress of changes commencing with the firing on a new case. It’s the “progress of degeneration,” in a way of looking at it because the concern is getting a handle on when enough change in the brass has come about to require attention. Or abandonment. As said then, for me that’s 4 firings. That, as said last time, is when I might see changes that need attention. Also as said, that figure didn’t come out of a hat, but from my own notes in running my competition NRA High Power Rifle loads.

The areas most affected are the case neck and case head area. Case neck walls get thicker, and that was the focus last time. Well, the case head area body walls get thinner. Primer pockets get shallower and larger diameter.

As started on: Brass flows during firing. It expands, then contracts, and when we resize the case, it contracts, then expands (a little). This expansion and contraction makes the alloy harder over the entire case, but with more effect in areas of more expansion, and flow. Replace “hard” with its effect, “brittle,” and that’s a clearer picture. This increasing hardness influences its reaction to being sized or otherwise stretched. As with many metals, bend it back and forth enough times and it will break. It will also fail if it loses enough resilience, or thickness, to withstand the pressures of firing.

Case Head
When a case is under pressure during firing, the brass, like water, flows where it can, where it’s more free to move. Of course, the chamber steel limits the amount it can expand. The case shoulder blows fully forward and the case base is slammed back against the bolt face. There is, therefore and in effect, a tug on both ends — it gets stretched. The shoulder area is relatively free to expand to conform to the chamber, but the other end, the case head area, is not. Since that’s the area of the case with the thickest walls, it doesn’t expand “out” much at all. What it does is stretch.

The “case head area,” as I refer to it here, is the portion of the case above the web, which is just above the taper that leads in to the extractor groove. The “area” extends approximately an eighth-inch up the case body.

case pressure ring
Here’s a “pressure ring.” You’ll see this after firing, if you see it. And, if you see it, that case is done. The bright ring indicates excessive stretching, which indicates excessive thinning.
head separation pic
Closer view of another sectioned case. This one here was fixin to pop. 

That portion of the case does not fully expand and grip the chamber, but the area immediately ahead of it does. So the case body expands and grips the chamber, and that last little bit back to the base can and does move. It stretches. If you see a ring circling the case, noticeable because it’s lighter color than the case body, and it’s in this area, I’d say that case is done. The ring will be evident after firing, not after; don’t confuse a shiny ring around the case in this area with what can be normal from sizing, especially if it’s been a hotter load. That is pretty much a scuff from the sizing die squeezing down this expanded area.

And that’s right where a “head separation” occurs. It can crack and also blow slap in two, and that’s the “separation” part of case head separation.

This is a spot to keep close watch on as cases age. It is also the area that is more “protected” by sizing with less case shoulder set-back. That is, pretty much, where the freedom for the stretching movement in this area comes from (the case shoulder creates a gap). However! As said many a time, semi-autos need some shoulder set back for function, and it’s the reason to use an accurate gage to determine the amount of set-back needed.

case head separation
Ultra-high-precision gage, made by me. Not really. It’s a selectively bent paper clip, and running this down inside the case and and then back up the case wall can signal a dip-in in the head area, which signals thinned walls. Feel it? Case is done.

Some folks unbend a paper clip and run it down inside a case and drag it up against the inside case wall as a sort of antenna to see if they detect a dip-in near the head area, which would indicate that the wall in this area has been stretched thinner. If there’s enough to feel it, that case is done.

Since I’m working off this “4 Firings In” checklist, if you’re seeing a sign that a head separation might be nigh in that few uses, chances are the shoulder set-back is excessive, and also too may be the load pressure level.

Primer Pocket
Another case-head-area and pressure-related check is the primer pocket. As said, the primer pocket will get larger in diameter and shallower in depth each firing. As with many such things, the questions are “when” and “how much,” and the main thing, “how much?”

If the pocket gets excessively shallow, and that’s judged by a primer that seats fully but isn’t at least a tick below flush with the case base, there could be function issues. There’s a risk of a “slam-fire” with a semi-auto that uses a floating firing pin, and, if there is actual protrusion, that has the same effect as insufficient headspace.

primer pocket uniformer
A primer pocket uniformer can reset the depth of a shallowed primer pocket to what it should be, but the real test for me is how easily the next primer seats into it. If it’s significantly less resistance, I’ll say that case is done.

Shallower can be refurbished. That’s a primary function of a primer pocket uniformer. Larger diameter, though, can’t be fixed. I’ve mentioned in another article or two that, any more at least, my main gauge of load pressure has become how much primer pocket expansion there’s been. I judge that without using the first gage, well, unless my primer seater is a gage. If a primer seats noticeably easier, that’s the clear clue that the pocket is too big. Another is seeing a dark ring around a fired primer, indicating a little gas leakage.

Measuring primer pockets is a waste of time, say my notes at least. First, it’s not easy to accurately (truly accurately) measure a pocket, especially its diameter, but, that’s not really what matters. It’s how much grip there is to maintain the primer in place during firing.

I pay close attention to resistance in primer seating and won’t reuse a case that’s too easy.

Good deal on what I think is good brass, especially if you’re an AR15 loader — HERE

Glen’s books, Handloading For Competition and Top-Grade Ammo, are available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

Glen’s newest book, America’s Gun: The Practical AR15. Check it out HERE

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RELOADERS CORNER: 4 Firings In

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Along with all the other operations we do to them, cartridge cases also need maintenance. A good question is “when”? That’s next… KEEP READING

old case

Glen Zediker

I tend to write much of what I do for those who reload for production. Those are folks expecting good utility in exchange for the expense and effort: a reliably-performing round of ammunition, over and over again. They’re loading and reloading because they like to shoot. It’s a big bonus to most, and I include myself in this group most of the time, if that good performance comes with a minimum of effort. Clean, size, prime, fill, seat, shoot. Five steps to get to the one thing that matters most: shoot! I am also in another group some of the time, not as often now as I once was, and those folks may add a few more steps before getting to the “shoot” part (case prep mostly).

It would be wonderful if that simple cycle endured without end. But it won’t.

Overall case condition after X-many firings varies A LOT because of a lot of factors, variables. What matters is getting a handle on it. I look over each case each time I load it, but I don’t break out the measuring tools. That’s not neglect. There is never (ever) any excuse for neglect. That’s not what this is about. It’s about working out a responsible, reasonable, and realistic schedule for when to take a close look at the progress in condition that new batch of cartridges cases has followed after some time.

In my experience, which is what’s in my notes, I say that’s 4 firings.

I went through the per-use checks enough times to know the schedule one brand and lot of brass, used with the same loads in the same barrel, follows with respect to changes. And by that I mean when changes require attention. I’m also starting with prepped cases, including trimming, before their first firing.

Let me make clear that I’m not suggesting that 4 firings is maximum case life! What I am suggesting is that this is the point where it’s likely to see measurable influences from use and reuse, and, as such, that it can be measured. That’s what we’re after now: take a check to see what’s happening, and that also is a big help toward getting clues about where and when these changes might get noticeably influential.

So, to be clear: the case has been fired four times, reused three times. Next loading, if there will be one, will be for the fifth use.

chamber reamer
We, or more correctly, our cases, are at the mercy of this thing: a chamber reamer. It sets the amount of space the case can expand into.

Changes
Continuing to use and reuse cases, we’re not really using the same cases each time. The cases change, and much of the change comes from material flow, which is brass.

Here’s how it goes, which is to say here’s how it flows: Case neck walls get thicker. The case head area body walls get thinner, over a short span of the body. Primer pockets get shallower and larger diameter. Overall, the alloy hardens over the whole case.

As gone on about a few times in this spot, there’s going to be more change in cases run through a semi-auto than those used in a bolt-action. That’s because of the necessarily additional (comparatively speaking) sizing and also the additional stress resulting from the firing cycle. There’s more flow because the cases are free to expand more.

drop bullet
A simple, and important, test to check if case necks walls have thickened excessively is to take a fired case and drop a bullet in it. If it won’t drop without resistance, stop! That’s way too much.

The Neck
All case necks expand to whatever the chamber allows. There’s no relationship between that and sized dimension because, clearly, there has to be a small enough neck inside diameter to retain the bullet. It is, though, one of the reasons case necks tend to give up quickest (plus it’s the thinnest-walled area on a case).

The case neck is my primary concern, and the first thing I check. If the walls get too thick it’s possible to cut the space too close between the case neck and the case neck area in the rifle chamber. There might be interference upon bullet release, and that creates excessive pressure, or sure can. All that depends on what the chamber allows for expansion room.

The most simple check is to see if a bullet will freely drop into a fired case neck. If it won’t, stop! Do not reuse that case as-is. A case that won’t pass this no-tool test has excessively thickened.

Somewhere in your notes should be a figure indicating loaded outside case neck diameter, on new brass. This dimension is exclusive of the sized neck diameter, because when the bullet is seated the neck is going to expand to accommodate the bullet. Another check of loaded outside neck diameter will show if there’s been thickening. If an inside neck sizing appliance is used (a sizing button), then that will tell you also, comparing it to what you also recorded for the new case after sizing it. (And it’s a good reason to always run new brass through your sizing die, even if it’s “ready to go” out of the box.)

I hope it’s clear enough why it’s important to “write everything down.” References, standards are big helps.

Direct checks of the neck walls themselves using a suitable tool will show thickening. However! Case necks don’t necessarily thicken the same over the entire height of the case neck cylinder. Remember, the brass is flowing so moves in a direction, and that part of the case has a wave going forward, toward the muzzle. There can and likely will be a tapering from thicker to thinner. Measure at more than one point.

Safety is one thing, and the most important thing, and then the other thing is accuracy. Case neck “tension” needs to be consistent from loading to loading to get reliable accuracy.

Fixing it? An inside case neck reamer is the easiest and most direct means. However! Make double-dang sure you know the numbers and therefore how and at what point to use it! Many are intended for use on fired (not yet resized) necks. Others are a specific dimension that you may or may not be able to specify. Thinning the case neck walls using an outside case neck turner is another direct remedy. A little tedious.

forster reamer
The best way I know to remove material to refurbish overly-thickened case neck walls is an inside case neck reamer. This is a Forster, designed to work with their case trimming base. Trick is knowing the case condition it was designed to be used with. This one is dimensioned for use on fired, unsized case necks (it’s 0.003 under bullet diameter). Run it on a sized neck and way too much brass comes off. Various sizes are available.

Reamer or turner, though, this job hasn’t finished until the refurbished case has been run through your usual sizing die, and checked again for diameter.

Well, so much for this here and now. Out of room! More next time…

See REAMERS HERE

Glen’s books, Handloading For Competition and Top-Grade Ammo, are available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

Glen’s newest book, America’s Gun: The Practical AR15. Check it out HERE

par15

RELOADERS CORNER: Improving Die Performance: 4 Simple Modifications

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Here are 4 low-to-no-cost setup tricks that will improve the concentricity of your loaded ammo. READ MORE

Glen Zediker

Cartridge cases and reloading dies all have centers. Trick is getting the centers to agree. When they do then that’s an asset to “concentricity,” and that’s attaining a major goal in the process of making better ammunition. A part that’s under pressure and moveable, such as a cartridge case being sized or a bullet being seated, moves toward a path of least resistance. If all associated tooling is “straight,” and the case itself is uniform, then the result is “straight.”

Accepting existence of tolerances and misalignments, taking steps to help two conflicting centers come close together comes from providing some free-play in the apparatus. I call it “floating,” and it serves to help, and here are a few ways.

To be clear: free-floating can help in two ways. One is to build-in float within the tool, and another is to create float and then use that to better center a tool. I’ll explain…

shellholder trick

1. Shellholder
Reloading presses with conventional shellholder arrangements use a spring clip to retain the shellholder in its slot. Remove it! It sits the shellholder off on an angle.

Get to a (real) hardware store and get an o-ring to secure the clip. The o-ring goes around the slot previously occupied by the clip. To install the shellholder just roll the ring down, slide in the holder, and the o-ring will pop back up to block  shellholder exit. Normally, the size needed is 7/8-inch outside diameter, 11/16 inside diameter, 3/32 thickness.

With the clip gone, the shellholder sits flat, as it should, and since the shellholder is free to move also allows some “wiggle room” so the cartridge case can center itself as it enters the die. This honestly makes a positive difference, especially in bullet seating, it seems.

NOTE: for these next “tricks,” choose a case that represents your “best,” one that’s got the most consistent neck wall thickness.

indexing dies on reloading press
Always put an index mark from die lock ring to die body to press top. That’s a simple way to verify return to “zero” when a die is installed back into your press. And ALWAYS install and remove the die holding ONLY the locking ring! Never the die body. Any bit of body rotation within the locking ring requires repeating the process of die adjustment.

2. Sizing die lock ring
Speaking of “wiggle room,” there’s just a little too much of that in a 7/8-14 thread. It’s pretty coarse. Taking up the play created by thread-to-thread gaps results in “straighter” die installation.

Always (always) secure a die body locking ring when there is a case inside the die, and with the ram in its fully upward position (press handle all the way down). This bit of pressure helps bring the die into better alignment. It also makes the die difficult to remove after snugging down the lock ring. Just get stout on it, and, after initial removal, subsequent re-fittings are easy. I use a “strap wrench” (plumbing supply and auto parts stores will have one). “Channel-Lock” pliers also work, but result in cosmetic, but not real, damage. Lock rings with wrench-flats are the bomb.

Before initial removal of the die after the snug-up step, draw an indexing mark from the die body to the die lock ring to the press top. That’s a simple way to return to “zero,” and also to know if anything got out of kilter. Use a paint marker.

3. Sizing button (expander) / decapping assembly
To get the sizing button in a sizing die holding on center, loosen the decapping stem lock nut and run a case fully up. Then slowly retract it until you feel the button enter and lodge into the case neck. Now. Put just a little pressure back in the “up” direction (down on the press handle) and then tighten the decapping stem lock ring.

This really makes a difference, by my notes.

adjust sizing die expander
When it’s possible, and it almost always is, secure the pieces-parts when they’re doing their jobs. For instance, tightening the locking rings on a decapping stem when the expander is holding inside the case neck helps bring the stem into straight alignment, and the expander along with it.

4. Bullet seater
Follow the same die-body-lock trick, after a bullet has been seated, and also just in the same as described for centering the sizing button (just keep the pressure “up” rather than retracting the handle) while you lock the seating stem. Flushing the die body makes a difference. Centering the seating stem may or may not, depending on the style of seating die you have. The “sleeve”-type seaters (like the Redding Competition) are already in alignment so the seating stem itself can’t be influenced. As said, the body can get a help.

index sizing die
O-ring trick: the flexible ring allows for some “wiggle room” to help case and die centers match. Trick is reinstalling the die to hold the desired setting, and the index mark really helps.

One more: Lock-ring o-rings
Here’s another trick I can suggest, but don’t really use… That’s because it, indeed “works,” but I prefer these other means. The trick: install an o-ring under the die body locking ring (for sizers and seaters). This allows some movement, positioning flexibility, in helping a case center as it’s entering the die.

If you do this one, most definitely index-mark the die ring to the die body and then the ring to the press top, as suggested. Never touch the die body itself to thread in or out the die. Hold only the lock ring! (And that’s true regardless.) O-ring size is 7/8-inch inside diameter and a thickness of 1/8-inch.

NOTE: My topics over the past few editions have tended be a tad amount “nostalgic,” and there’s some reason. I just finished a new book, and this one took me way on back to the start of when I discovered reloading, which coincided with discovering my first AR15. It’s called “America’s Gun: The Practical AR15.” It will be available here soon, but not just yet. But go take a look! Information is on my web site HERE. I’m really proud of it. 

This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

RELOADERS CORNER: What Happened To Moly-Coated Bullets?

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All the rage in 1998 and all but dead 2018: here’s a look at some reasons why. KEEP READING

moly coated bullets

Glen Zediker

In a way, I guess nothing really happened to molybdenum-disulfide-coated bullets (“moly-coated”). They’re still for sale, as are means to make up your own. What I mean is why didn’t they attain the sustained popularity they started with about 20 years ago, back when many forecasted they would virtually replace bare bullets? Here’s my take, from my experience, on “what happened.”

I don’t know any shooter who tried them and wasn’t excited about results. I sho was!

Performance-wise, moly has a lot of benefits. A lot. The first and most: take two bullets, one coated and one bare, put the same load behind them, then shoot and chronograph. The coated bullet goes slower. How is that a help? The reason it goes slower is because moly drops chamber pressure (into and through the bore easier). And! That velocity loss (at least 50 fps, usually more) is not, proportionately, nearly as much as the accompanying drop in pressure (usually ballpark 4000+ psi). (These figures vary with the cartridge, but all show similar universal influence.) So. The moly-load can be increased beyond previous “maximum” velocity: the idea is to take the coated load up to normal chamber pressure. It works! It’s common to need at the least 1+ grain more propellant to level the coated load with the original bare-bullet load.

Other advantages: Most see improved velocity consistency, evidently resulting from the coating alone. The coated bullets seem to have no limit to the number of rounds that can be fired with no change in accuracy or impact location. Of course there is a limit, but I knew many going beyond 500 rounds between cleanings. And when I say “many,” I’m talking about serious competitive shooters. Another benefit is increased barrel life (less rapid throat erosion), and this is, I think, due to a faster-accelerating bullet getting into and through the throat more quickly (less intense flame). Moly bullets also release sooner from the case neck (additional “tension” is recommended).

I “switched.” (The motivation to write this came from a weekend shop-cleaning where I restacked a huge many boxes of coated bullets, and wondered if I’d ever shoot them…)

I got more bullet speed and zero loss of zero: big benefits to an NRA High Power Service Rifle shooter. 88 rounds per day, and 80gr bullets through a 20-inch barrel trying their best to get to 600 yards in close proximity of one another.

moly barrel cleaning
Here was my solution to cleaning up after moly: Kroil penetrating oil and abrasive-type bore paste. This combination got it gone, and zero didn’t leave in the process.

What is bad, then, about moly-coated bullets? Moly itself! It coats the bore with a layer of residue. This layer traps moisture and will, not can, corrode the steel underneath it.  More: molybdenum disulfide outgases (outgas is the release of an occluded gas vapor that was part of the compound; a state change, pretty much) at lower than firing temperatures. That creates a chemical that, when mixed with water (including post-firing condensation), becomes, pretty much, sulfuric acid. That meant that the whole “zillion rounds between cleanings” didn’t really work. I know many who “lost” barrels, expensive barrels.

If the barrel is cleaned (correctly) after each use, no problems. But then another advantage is lost because starting with a clean barrel it takes quite a few rounds to return to zero. The layer has to be recreated.

The residue is x-difficult to remove. It doesn’t respond to routine means for bore maintenance, mostly meaning brush-and-solvent. The only way I found to get it gone was using micro-penetrating oil in conjunction with an abrasive paste-type cleaner, such as USP Bore Paste or JB Bore Compound.

bn coated bullets
Boron Nitride (BN) is an alternative that functions, in my experience, the same but with fewer drawbacks. One is that it’s “clear,” not as messy. Bullet on the left is coated. Still, though, I think that shooting coated bullets is an “all or nothing” proposition. Good groups are not likely to come “mixing” bare and coated bullets through the same barrel.

I no longer use coated bullets. There are other coatings that have fewer disadvantages, like boron-nitride (doesn’t outgas), and some of the proprietary baked-on coatings a few major makers (like Barnes and Winchester) use don’t exhibit the post-firing issues “conventional” moly-coating creates (which usually was moly powder, followed by wax, which added to the tenacity of the residue).

However, another issue is that accuracy tends to suffer running bare bullets though a residue-coated bore (which results after only a few coated rounds, that are coated with anything). All that means, in short, is that running coated bullets is something that really has to be bought into. It’s a commitment, as I see it, and, as with many such things, pushing the limits on performance requires more attention to detail, more effort. It’s a matter of value.

lyman moly kit
Here’s an easy way to get bullets coated: Lyman’s Super Moly Kit. Just add a tumbler. The two bowls contain the media, moly, and bullets and then go into a vibratory-type tumbler. The 6 ounces worth of moly powder will coat thousands of bullets. It works well.

Weigh the pros and cons. I honestly cannot, and will not, tell anyone not to use them. Coating can provide a serious performance increase. I don’t use moly-coat anymore, but that’s because my shooting needs are not so “serious” as they once were. I, yes, have gotten a tad amount lazy. I want to go to the range and enjoy my rifles and not lose sleep over the possibility of creeping corrosion if I didn’t clean up. I also want to be able to shoot different loads, including factory ammo, and maintain accuracy.

Last words: IF you choose moly, take steps to protect the barrel bore against the potential for damage. At the least, run some petroleum-based oil through the bore after shooting if you can’t clean it soon.

Tell about your experiences with moly.

See what Midsouth offers HERE

This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

RELOADERS CORNER: Cartridge Cases, the Outside, Part 2: Case Cleaning

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Clean means “not dirty.” More details coming next. READ IT ALL

clean cases

Glen Zediker

Clean brass loads easier, keeps dies cleaner (and may help them last longer), and might even help your barrel last longer. Brass collected up off the ground almost always has some manner of grit clinging to it and, depending on range locale, that will cause more or less concern. If it’s sand, for instance, this debris can do serious damage to a die (and barrel). Plus, I’ve never had a semi-automatic that didn’t soot up the case neck and shoulder. And, since we’re needing to lubricate the whole case prior to sizing, there’s no place for gunk. As said last time, case lube should not be a case cleaner!

There is also always going to be firing residue, if not on the case, it will be inside the case, and in there will also be primer residue, which is very abrasive.

Brass doesn’t have to be polished to be cleaned, which is to say that it doesn’t have to be shiny to be clean. Get down to the bare metal and that’s “clean.”

The question is How?

Not counting all the methods and means I’ve heard tell of, which number well over a dozen, the two common are either dry media or liquid media. Dry media is most commonly corncob or walnut, and run through a rotary- or (more popularly) vibratory-style appliance. There’s another I’ve been impressed with and that is the use of steel media, and more in a bit.

corncob media
Good old corn cob works just fine, but make sure you get all the residues off the cases.

Liquid means can revolve around detergent-type solutions and agitation, or the “sonic” cleaners.

General: Advantages to dry media are, well, that it’s dry! Not (as) much mess. Disadvantages exist, however. The main one is getting all the residual dust and particulate out of the cases. I caution against using any additional abrasive additives to the dry media because what doesn’t get cleaned away will, not can, accompany a bullet down a barrel. Advantages to wet media are that it can do a thorough job of cleaning, no doubt. It also doesn’t leave any residue. But! It’s wet! And that means the cases need dried thoroughly prior to reuse. There are specialty appliances that can do it, but a cookie sheet in an oven set on “low” does the trick too.

hornady case cleaner
Hornady Sonic Case Cleaner

Back to the steel: That’s why I like this method. Dry, no residue. It in no way hurts the cases, and works pretty quickly.

steel case cleaner
A newer dry media is steel. It works well and leaves nothing behind. This magnet is how you separate media from cases. This one is from Frankford Arsenal

No media lasts forever. Corncob, especially, should be routinely discarded and the appliance cleaned out to avoid any resident grit mingling with the media particles. Much as in the same way gold panning works, heavier junk can settle to the bottom of the bowl. Tumbling media, by the way, doesn’t really wear out: it just gets crudded up.

Take steps post-cleaning to ensure that residues are gone, and also that primer pockets are free of particles. Some use compressed air to blow out the case inside, and others go as far as to rinse and dry.

Speaking of primer pockets! I very strongly suggest decapping prior to cleaning. That way the pocket will, indeed, be cleaned. This doesn’t take much time and requires only an inexpensive station as shown nearby.

decaping die
I strongly recommend decapping primers prior to cleaning. A setup like this doesn’t cost much, and the operation is pretty painless.

Additional steps? There are some long-used steps taken especially by precision shooters, such as brushing the inside of case necks, and also using a polishing cloth to thoroughly clean the case neck, case shoulder area, and separate attention paid to the pimer pocket. But. These steps originated with Benchrest competitors and the reason is because I never met one yet who uses the short of cleaning apparatus “we” use. Never a tumbler! Their cases never hit the ground either. Nothing more than a thorough run through the volume-cleaning media of your choice should be needed, and the primer pocket cleaner should likewise be unnecessary if you take the advice of cleaning deprimed cases.

Honestly, it’s better, and I say best, if the case cleaning media leaves no residues. That’s where dry steel media and the liquid cleaners come in.

Back to the basics: Clean is clean. “Nothing but brass” is “clean.” Polished and gleaming cases are not necessarily better, and matter not a whit to performance.

One last: my favorite case cleaning “story” ever. Middleton Tompkins, many-time Highpower Rifle national champion, showed me his case cleaning method on a visit. Mid (and his wife, dominant Long Range Rifle winner, Nancy) go well beyond “high volume” in their needs for clean cases. To that end, Mid purchased a small commercial cement mixer into which he dumped pounds of BBs and a solution of Joy dishwashing soap and water (later rinsed and drained and dried). Now, that’s a high-volume case cleaner!

Check out Midsouth products HERE

And decapping DIES!

This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

 

RELOADERS CORNER: Cartridge Cases: The Outside, Part 1

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Lubrication is absolute essential in the reloading process, Here are a few ideas on which and how. READ MORE

lubing cases

Glen Zediker

What’s the most important thing in case resizing? Case lube! Overlook it or under-do it once and you’ll know why! A stuck-case remover is one of my very least favorite tools…

I have long used and recommended petroleum-based case lubes. More: I prefer those that are applied by hand, literally with the fingers, because I think it’s a better assurance that the right amount, to all the right places, will get laid down. I will quickly concede, though, that they are messy and slower than other methods.

imperial case lube
This is my favorite case lube. I took advice from Sgt. Norris after complaining how hard it was to get a good sizing pass on a Lake City .308. Sure enough. This made it easy. Been using it ever since. It’s not really wax. Use it like shoe polish: rub a little on your fingers and then rub it onto the case with a “gimme money” motion.

Spray-on-type lubes are very often used and recommended, especially by high-volume loaders because a good many cases can be treated and then even stored before use, so say the claims. I strongly suggest taking steps to prevent the lube from finding its way inside the case. A thin piece of cardboard placed atop the standing cases works well for this. There’s worry otherwise that the lube might affect the propellant. That does depend on the formulation, but I prefer the “no-chance” approach. I’m a “slow-down” sort of loader. That doesn’t mean I don’t want to save time or be as efficient as I can be, but I’ve just not found the speed advantage to spray-ons to overcome their performance. Sprays are not quite as “slick” as rub-ons.

Lanolin-based and wax-based alternatives also have their following. As do water-based lubes. The wax lubes indeed work and also clean up (off) easily, as does lanolin. I’ve not been a follower, though, because I find many to be more difficult to apply evenly and, one more time, just not quite as slick at petro-based products. Some of the wax-based lubes also make claim to “apply-now, use later.” I’m not sure what the appeal of that is, but there it is for those it appeals to. There are also a number of “proprietary” formulations out there now. I have not tried them all.

hornady case lube
Hornady pretty well has it covered: one for every opinion! Try them all! But I will wager you’ll like petro best… That’s the one in the bottle. Hornady claims their spray lube doesn’t contaminate powder, and that makes it applying it more straightforward.

A tip I picked up umpteen years ago by the man who got me started loading was to get an ink stamp pad (office-supply store variety) to apply roll-on type lubes. Indeed, that works way better than the industry pads I’ve tried.

Back to petroleum lubes: aside from providing smoother feel in sizing, which I have to believe also indicates “better” lubrication qualities, these don’t build up as much within tooling. I take apart my sizing die every now and again and swab it out, like I would a rifle chamber.

For best results, no matter which lube type you’re using, an even (thin) coating gives best results. With a good petro lube, it doesn’t take much. If you see any denting (usually in the case shoulder area), that resulted from hydraulic pressure and is a sign there was too much lube (too thick a coat). No worries, though: shoot the case and they’ll iron back out. Just use less lube next time!

Lubing the case neck inside is debated, but I favor it. However! Only very sparingly! That is why I really like the finger-applied lubes: just a little “wipe” across the case mouth eliminates the “gaunch” noice from the expander. I don’t use the graphite-applicators (the bin-and-brush types) because I haven’t noticed a whopping lot of difference in neck sizing with or without it.

forster lube
For best sizing results, I prefer the “rub-on” lubes. This one is from Forster. Never any worries about too much, too little, or complete coverage.

And, by the way, lube a case each pass through the die. This is important when setting up a sizing die where you might make a few passes with the same case. Don’t risk it! Stuck cases are total mood killer.

Clean the lube off the cases! There will be some now who will just roll their eyes, but I use denatured alcohol and a bath towel pour some on the towel, but the cases on the towel, fold the towel over the cases, and roll them around. Fast and simple! That works for petro-based. Others need more attention: just rub it away, or use detergent.

I do not recommend using a tumbler-type cleaner on loaded ammo!

Sho, there is a (slight) chance that a bullet tip might detonate a primer, but that’s not why. Why is because the propellant gets pulverized, and that, no doubt, will change its burn characteristic.

case cleanup
This is what I use to clean loaded rounds, along with the towel it’s sitting on. Lay out the towel, put down the rounds, pour some alcohol, fold the towel over the cases, and roll them around. Then hang the towel to dry for another use. Zero residue.

The reason to clean off the lube is because it lubricates, and that’s a bad thing on a live round. The case is supposed to stick tightly to the chamber when it expands under pressure. Any slip increases bolt thrust. I once saw a fellow douse a loaded 30-round magazineright down the middle with WD-40, to “make sure the bullets fed…” NO NO NO. Oil on a cartridge doubles bolt thrust!

Case lube is not a case cleaner!

Make sure the cases are clean prior to sizing. They don’t have to gleam, just be free from dirt and gritty dust. If you’re seeing a applicator pad, for instance, getting a dirty spot on it, well there’s your clue.

We’ll talk about that next time.

 Check out the selection from Midsouth HERE

This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

RELOADERS CORNER: Primer Tech

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It may be the single-most influential reloading component, so learn all about it: the primer! READ MORE

rifle primer

Glen Zediker

This is one component in the collection that might not get all the attention it warrants. That’s because it is the one thing, above all other components, that you don’t want to just swap and switch around.

We’ve all heard cautions about testing new lots of every component, especially propellant, but primers not only change lot to lot, they vary greatly in their influence on any one load, brand to brand. The difference in one brand to the next can equal a good deal more or less pressure, for instance. While there are “general” tendencies respecting the “power” of various-brand primers, always (always) reduce the load (propellant quantity) when switching primers.

This has become more of an issue over the past few years as we’ve faced component shortages. I can tell you without a doubt that going from a WW to a CCI, or from a Remington to a Federal, can have a major influence on a load. I establish that from chronograph readings. No doubt, it’s best to have a good supply of one primer brand and lot that produces good results, and when that’s not possible, it’s a hard sell to convince someone to stop loading ammo and get back to testing. But. It is important. I can tell you that from (bad) experience. How I, and we all, learn most things…

When I switch primers, whether as a test or a necessity, I reduce my load ONE FULL GRAIN. There can be that much effect.

The Thing Itself
A primer is made up of a brass cup filled with explosive compound (lead styphate). Lead styphate detonates on impact. Primers don’t burn – they explode! In the manufacturing process, this compound starts as a liquid. After it’s laid into the cup, and while it’s still wet, a triangular piece or metal (the “anvil”) is set in. When the cup surface is struck by the firing pin, the center collapses, squeezing the explosive compound between the interior of the cup and the anvil. That ignites the compound and sends a flame through the case flash hole, which in turn lights up the propellant.

Primers are dangerous!

Don’t underestimate that. I’ve had one experience that fortunately only created a huge start, but I know others who have had bigger more startling mishaps. These (almost always) come from primer reservoirs, like fill-tubes. Pay close attention when charging up a tube and make sure all the primers are facing the right way, and that you’re not trying to put in “one more” when it’s full! That’s when “it” usually happens. What will happen, by the way, is akin to a small grenade. Static electricity has also been blamed, so keep that in mind.

primer tray
Take care in filling primer tubes! Make double-sure all are facing correctly, and a good primer tray helps. This photo shows the correct orientation for using primers one at a time. To fill a primer tube, make sure the “shiny side” is facing up! Flip the tray over.

Sizes and Types
Primers come in two sizes and four types. “Large” and “small”: for example, .223 Rem. takes small, .308 Win. takes large. Then there are pistol and rifle in each size.

Rifle primers and pistol primers are not the same, even though they share common diameters! Rifle primers should have a tougher cup, and, usually, a hotter flash. Never swap rifle for pistol. Now, some practical-style competitive pistol shooters using their very high-pressure loads (like .38 Super Comp) sometimes substitute rifle primers because they’ll “handle” more pressure, but they’ve also tricked up striker power. That’s a specialized need.

Further, some primer brands are available with a “magnum” option. Some aren’t. My experience has been that depends on the “level” of their standard primer. A magnum primer, as you might guess, has a more intense, stouter flash that travels more “deeply” to ignite the larger and more dense powder column. It reaches further, faster.

large rifle primers

large rifle magnum primers

There’s no real reason not to experiment with “hotter” and “colder” primers, whether the case is stamped “mag” or not. Keep in mind that the experiment is all about the initial flash effect. And keep in mind that this (without a doubt) demands a reduction in the propellant charge at the start.

Over a many years I’ve seen some tendencies respecting flash effect. Using routine cartridges, like .308 Win., single-base extruded propellants tend to shoot well with a cooler spark to start, and the double-base, especially spherical-types, seem to respond best to a hotter flash. Many seem to think that the coating (necessary to form the spherical) and the inherent greater density (less air space between granules) in a spherical demands a little faster start.

Flash consistency is very important, shot to shot. The consistency of every component is important: bullet weights, diameters, case wall thicknesses, and all the way down the list. We’re hoping to get more consistent behavior from a “match” or “benchrest” primer, and we’re paying more for it. I can tell you that some brands that aren’t touted as “match” are already consistent. That all comes from experience: try different primers, just respect the need to initially reduce the load each test. I can also tell you that my notes tell me that the primer has a whopping lot to do with how high or low my velocity deviations plot out.

One last: there are small variations in primer dimensions (heights, diameters) among various brands. These variations are not influential to performance. But! Small diameter variations can influence feeding through priming tools. This can be a hitch especially in some progressive loading machines. Manufacturers usually offer insight (aka: “warnings”) as to which are or aren’t compatible, so find out.

Check out Midsouth products HERE
Primer trays HERE

This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com