RELOADERS CORNER: 4 Firings In

Facebooktwittergoogle_plusredditpinterestlinkedintumblrmail
Facebooktwittergoogle_pluspinterestyoutube

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

Facebooktwittergoogle_plusredditpinterestlinkedintumblrmail

14 thoughts on “RELOADERS CORNER: 4 Firings In”

  1. Great article on additional case prep checks on 4th reloaded fired cases. I also check after every firing, the case head area inside the case with a modified large paper clip feeling for any signs of possible case head separation beginning on the cases. If any is found the case goes into a bucket for recycling. This article is sound advice by Glenn to follow.

    1. I would be interested to know more about your “neck tension gauge.” Truly?

      I thought I had every tool ever made for making rifle cartridges?

  2. In the photos with the hands, cases, and bullets, part of the caption underneath the photos reads, “………… If it won’t drop without resistance, stop!……….”. This is hard to understand. Can you please restate this so that I can understand it? Maybe say something like, if it drops with resistance or if it drops without resistance. Thank you.

    1. I agree PATRICK. I don’t know what he is trying to say. On the one hand it sounds like the bullet SHOULD fall into the case when tested in an unpreped state. Then he continues with the case thickening with out telling what part of the case.

    2. 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…

    3. I honestly don’t understand how the author could make this clearer? Fired case. Drop 0.308″ bullet down neck. If it does not just “drop into” the case, then you have a wall thickening problem.

      I’ve been reloading rifle cartridges for over 35 years, and this never occurred to me.

      I think it is an awesome observation.

  3. Love the reading articles. Any advice even if it’s something you have not thought about for a while can be helpful. One thing mentioned that I found over ti.e to be extremely important with reloading is to keep organized notes. I keep a diary of sorts on each rifle I am serious about reloading for and another book of measurements and observations. You can not have too many details in my opinion.

    1. I have rifle and handgun reloading data forms in both Excel and PDF format.

      Anybody wants it? ping me at:

      pcwhocares at yahooooooooooooo dot slam.

      (there’s no SLAM. it ain’t hard to figure. Just don’t want to post an email address that will get scooped up by the **sholes.

  4. I honestly don’t understand how the author could make this clearer? Fired case. Drop 0.308″ bullet down neck. If it does not just “drop into” the case, then you have a wall thickening problem.

    I’ve been reloading rifle cartridges for over 35 years, and this never occurred to me.

    I think it is an awesome observation.

Leave a Reply

Your email address will not be published. Required fields are marked *