Category Archives: Ammunition

ammo, or ammunition category will be host to all topics related to factory ammo and ammunition. Everything from 22 LR to Bulk Pistol Ammo will be discussed here.

Load Testing Insight: 5 “Rules” for Load Work-Up

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Don’t waste time and money collecting half-boxes of “loser loads.” Here’s how to start and finish load work-up in one day.


Glen Zediker


Last time I talked a little about keeping your ammo pressure-safe, under a range of conditions. Quite a bit of that dealt with observations made during load work-up. So this time I’d like to talk more about the work-up process I use.

The reason for the term “work-up a load” is pretty clear: we’re almost always looking to get the highest velocity we can, safely. High velocity, or, more clear, higher velocity, is usually all good. Shorter time of bullet flight to the target means less drop and drift, and a harder impact.

So working up means increasing propellant charge incrementally until we’re happy. Happy with the velocity or happy that the cases are still able to hold water. Ha. As said last time, it’s vitally and critically important to have a stopping place, a goal to be reached, prior to testing.

I also mentioned an “incremental” load work-up method that I have followed for many years, and it’s served me very well. I do all my testing and work-ups at the range. I load right then and there. I take boxes of sized and primed cases, and my Harrell’s powder meter, and a small press that I c-clamp to a bench. The press, of course contains my seating die. And the most important pieces of gear are a notebook and a chronograph.

load at the range
You don’t have to invest a fortune to take your handloading show on the road. Some c-clamps and one of these little Lee Reloader presses is all you need! And a good powder meter. One with a clamp is handiest, or just mount it to a piece of wood and clamp that down (even a pickup tailgate works just fine).

Before the trip, I have taken the preparation time, done the homework, to know exactly how much “one click” is worth on my meter. It varies with the propellant, but by weighing several examples of each click-stop variation (done over at least 4 stops) I can accurately increase the charge for each test a known amount.

reloading at the range
I map out the incremental values of each click on my Harrell’s meter adjustment drum with the propellant I’ll be testing, and it’s really easy to step up each trial with confidence. I carry the whole kit in a large tackle-type box.

I work up 0.20 grains at a time. Sometimes it’s more if I’m reading a low velocity initially. Since I have a meter with a “Culver” insert, which I trust completely, I actually reference the number of clicks in my notes rather than the weights. I check after the weights when I get back home, and I do that by counting to the setting and weighing the charge. It’s easy enough also to throw a charge into a case and seal it over with masking tape.

I started loading at the range because I got tired of bringing home partial batches of loser loads. And, you guessed it, the partial boxes usually contained recipes that were too hot. The only way to salvage those is to pull the bullets. Tedious. Or they were too low, of course, and fit only for busting up dirt clods. Plus, I’m able to test different charges in the same conditions. It’s a small investment that’s a huge time-saver.

During my work-up, I fire 3 rounds per increment. As it gets closer to done, I increase that to 5. Final testing is done with 1 20-round group. Does 3-round volleys seem inadequate? It’s not if there’s confidence that the rounds are being well-directed and speed is being monitored. If I’m seeing more than 10-12 fps velocity spreads over 3 rounds, I’m not going to continue with that propellant.

Here are a few things I’ve found over the years to better ensure reliable results. Learned, of course, the hard way.

  1. Limit testing to no more than one variable. I test one propellant at a time, per trip. If you want to test more than one on one day, bring the bore cleaning kit and use it between propellant changes. Results are corrupt if you’re “mixing” residues. Same goes for bullets. Otherwise, though, don’t clean the barrel during the test. Don’t know about you, but I fire my most important rounds after 60+ rounds have gone through it, so I want a realistic evaluation of accuracy (and zero).
  1. Replace the cases back into the container in the order they were fired. This allows for accurate post-testing measurements. Use masking tape and staggered rows to identify the steps. I use 100-round ammo boxes because they have enough room to delineate the progress.

    ammo pressure
    Keep track of the cases in the order they were fired. This helps later on back in the shop when the effects can be measured. This little outing here, though, didn’t require a gage to cipher: a tad amount hot on that last little go around (last case bottom row on the right). Thing is, I didn’t load a whole boxful of those chamber bombs to take with me, and that’s the beauty of loading right at the range.
  1. Use the same target for the entire session. (Put pasters over the previous holes if you want, but don’t change paper.) This helps determine vertical consistency as you work up (when you’ve found a propellant that shows consistency over a 3-4 increment range, that’s better than good).
  1. Exploit potentials. If you take the lead to assemble a “portable” loading kit, the possibilities for other tests are wide open. Try some seating depth experiments, for instance. Such requires the use of a “micrometer” style die that has indexable and incremental settings.
  1. Go up 0.20 grains but come off 0.50 grains! Said last time but important enough to say again here. If a load EVER shows a pressure sign, even just one round, come off 0.50 grains, not 0.10 or 0.20. Believe me on this one…

Last: Keep the propellant out of the sun! I transport it in a cooler.

shooting chrony
Chronograph each round you fire. It doesn’t have to cost a fortune to get an accurate chronograph. This one is inexpensive and, my tests shooting over it and my very expensive “other” brand chronograph (literally one cradled in the other) showed zero difference in accuracy. The more expensive chronographs mostly offer more functions. The muzzle-mounted chronos are fine and dandy too.

The preceding was a specially adapted excerpt from the new book, Top-Grade Ammo by Glen Zediker. Check it out at ZedikerPublishing.com or BuyZedikerBooks.com

Just Announced! New Hornady 2017 Products

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Christmas came early for those of us who follow Hornady, with their announcement of new products to expect in 2017. Let’s kick things off with the product launch video. Just a head’s up, it’s a beefy video, with tons of products listed, so if you want to break it down into multiple parts, then Click Here.

WOW! Here’s a few of the big takeaways we’re excited about…

Reloading-

Case Prep Duo:

Let’s start with the Case Prep Duo. Chamfering and deburring will be afar easier process with this handy little tool, with handy being the operative word. The swivel handle allows what is essentially a powered hand drill, to turn into a table top case prep station, stabilized by two rubber feet.

The Hornady case prep duo

Lock-N-Load® AP Tool Caddy:

Keep your commonly used reloading hand tools in easy reach with the L-N-L Tool Caddy. Swivel the arm to accommodate a righty or a lefty, then fill the arm with whatever tools you need to keep you focused on the task at hand.

the lock n load ap tool caddy

Ammunition-

America’s gun runs on black

Best said by Neil Davies, Hornady Marketing Director, “Without a doubt, black guns are the most popular firearms in America right now…” Hornady took this fact to heart, and began to make ammunition which would optimize the performance of America’s favorite guns. “Loaded with legendary Hornady® bullets, Hornady BLACK™ ammunition is designed to fit, feed and function in a variety of platforms. Direct impingement, gas piston, suppressed, unsuppressed, inertia, bolt, pump, supersonic, subsonic, rifle, mid-length, carbine or pistol – Hornady BLACK™ ammunition delivers superior performance for a variety of applications. Made in the USA.”

Hornady Black Ammo

Click Here for a full list of the offered ammo.

Bench Necessities-

Hornady® Reloading Handbook: 10th Edition:

One of the most valuable tools to any reloader, is knowledge, and what better way than with over 1,000 pages of well over 1,300 loads, including some new ones, like the 280 Ackley Improved, 7×64 Brenneke and the 338 Federal.

the new hornady reloading manual 10th edition

We’ll be reporting, in-depth, on the multitude of new Hornady products hitting the shelves soon, as well as a timeline as to when you can expect them to appear for purchase at Midsouth Shooters Supply. Stay Tuned!

Did you watch the whole video? Was there a product mentioned you’d like more info about? Let us know in the comments!

5 Steps to “Pressure-Proofing” Handloads

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Here’s a few ideas on how to proceed in load testing to find the safe maximum velocity, and keep it safe…

We’ve chosen the sometimes twisting path to becoming handloaders because we want to improve on-target results. The difference between a handloader and a reloader? My wise-crack answer, which is honest, is that handloaders start off with new brass… We’re not about to shoot factory ammo.

Part of the process of developing the load we’re seeking is learning how to safely set a cap on its pressure. Most of us don’t have pressure-testing equipment, so we rely on measurements and observation to know when we’re at the limit. The goal often, all other things being the same, is to find the highest velocity we can get. Less drift and drop, shorter time of flight, all good. However! Knowing that the maximum tested velocity is also going to be safe over the long haul is a much narrower line to walk.

There’s not room here to cover every pressure check, all the symptoms that can point out over-pressure ammo, but I’ll share my two leading indicators: primer pockets and velocities.

  1. Always start load development with new brass! There are a few reasons, but the leading one related to this material is that the primer pockets will be at their smallest. So. Fire the cases, size the cases, and seat new primers. It takes a little experience, which means a few times through this process, but my leading indicator of pressure is how easily the primers seat. They’ll go in easier than on the first use, but if there is much less to very little resistance felt the second time around, that load is over-pressure. Period. The case head has expanded (I put a max of 0.0005 on expansion, when it’s measured with a micrometer). The more you use the same cases and repeat this process, the sooner you’ll get a handle on the feel to know when the primer pocket has overly expanded.
seating primer to check pressure
My primary gauge for pressure is primer seating — how easily a new primer seats into a once-fired case. This is an indication of case head expansion. It won’t be as tight as new, but it should still be snug. A low-leverage tool, like this Forster Co-Ax, increases the feel and feedback of this operation.
  1. Jump back, don’t step back. If you encounter a pressure symptom, come off a “whole” half-grain. Not a tenth or two. And if you see it again, come off another half-grain. Folks, if anyone thinks the difference between over-pressure and safe-pressure is 0.10-grain, that same little bit exists in the difference in 20-degrees ambient temperature with many propellants. Don’t cut it that close. Keep the long-haul in mind.
  1. Select a temperature-insensitive propellant (related to the above). There will be one out there you’ll like. I use a single-base extruded (stick) propellant when loading for the season. The propellants I choose are coated to help reduce temperature-induced changes. That season is going to span a 50+-degree range, and I don’t want August (or October) to force me back to the loading room… Temperature sensitivity works “both” ways, by the way… Hot or cold can induce pressure increases.
  1. Read the speed on each and every round tested. Beforehand, I have to assume you’ve gotten an idea in mind of what you’re looking to get for a muzzle velocity. If not, do that… A journey of this nature has to have a destination. If not you won’t know when you get there. If you are reading velocities more than 40-50 feet per second over a published maximum, that’s a flag. That 40-50 fps is usually about a half-grain of most propellants in most small- to medium-capacity cases. Certainly, there are all manner of reasons some combinations can vary, but, despite what your mother might have told you, you are really not THAT special…
  1. Don’t assume anything. If you have one round out of many that “suddenly” exhibits pressure symptoms, don’t guess that it’s just a fluke. It’s not a fluke. You finally saw it. Overwhelming chances are that the load is over-pressure and has been over pressure, and the question is how much for how long? Back it off. (The way you know it might have been a fluke, and that happens, is again based on how close to a velocity ceiling it is: if it’s a real mid-range velocity load, it might have been a fluke.)
primer indicators for over-pressure ammo
Some over-pressure indications are pretty clear. Left to right: new, nice and safe (notice there’s still a radius on the primer edge), cratered and flat, yikes! It’s another article, but not all piercings are caused solely by high-pressure ammo; an overly large firing pin hole size in an AR15 bolt contributes.

One last about primer appearances. Usually the first thing a handloader will do after firing a round is look at the primer. I do. No doubt, if the primer is flattened, cratered, pitted, or pierced that’s a honking red flag, and the immediate response is, you guessed it, come off a “whole” half-grain. However. Small rifle primers (especially some primers in some cartridges) do not exhibit the common over-pressure appearances. They can look just fine and shiny until they blow slap out. If you ever see anything that looks like a pressure symptom, back it off; however, don’t assume a load can’t be running hot if the primers don’t show it.

over pressure ammo, primer appearance
Here’s what I mean about primer surface indications not always revealing high pressure. The middle one is an incredibly over-pressure load fired through one of my AR15 race-guns with an extra-heavy bolt carrier. Primer looks just fine. Right hand case is what happened without the extra weight. Neither case would hold a primer after this one firing.

Back to the start: primer seating and velocity are the leading indicators.


The preceding contains specially-adapted excerpts from the new book “Top-Grade Ammo” by Glen Zediker and Zediker Publishing. See it by visiting ZedikerPublishing.com.

7.62X51 vs. .308 Win.

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By Glen Zediker:

I hope by now that most folks do know there is a difference between 5.56 NATO and .223 Remington. Either way, I’ll be hitting that topic eventually, and the reason is because it really matters! Continue reading 7.62X51 vs. .308 Win.

Ammo Handling

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By Glen Zediker:

Last time we talked about case lube, and also about getting it gone. This time, let’s talk about storing ammo. Concerns and cautions aren’t necessarily only applicable to those looking to store a lot of ammo for a very long time. Nope. Ammo can “go bad” pretty quickly. Continue reading Ammo Handling

Hornady Announces 4DOF Trajectory Calculator

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Hornady has announced the launch of the new Hornady 4DOF (Four Degrees of Freedom) Ballistic Calculator.

The Hornady 4DOF calculator provides trajectory solutions based on projectile Drag Coefficient (not ballistic coefficient) along with the exact physical modelling of the projectile and its mass and aerodynamic properties. Additionally, it is the first publicly available program that will correctly calculate the vertical shift a bullet experiences as it encounters a crosswind—referred to as aerodynamic jump.

According to the company, the use of drag coefficients, correct projectile dynamics, aerodynamic jump and spin drift enable the Hornady 4DOF ballistic calculator to be the most accurate commercially available trajectory program available, even at extreme ranges.

The Hornady 4DOF Ballistic Calculator is available free at: https://www.hornady.com/team-hornady/ballistic-calculators/#!/4dof

“Current ballistic calculators provide 3 degrees of freedom in their approach; windage, elevation and range, but treat the projectile as an inanimate lump flying through the air,” said Dave Emary, Hornady Chief Ballistician. “This program incorporates the projectile’s movement in the standard 3 degrees but also adds its movement about its center of gravity and subsequent angle relative to its line of flight, which is the 4th degree of freedom.”

Using Doppler radar, Hornady engineers have calculated exact drag versus velocity curves for each bullet in the 4DOF calculator library. Combined with the physical attributes of the projectiles, the 4DOF calculator is simply more accurate for long-range hits than using BC based systems or custom drag curves based off of limited data collection points.

“This calculator doesn’t utilize BC’s (Ballistic Coefficients) like other calculators,” added Jayden Quinlan, Hornady Ballistics Engineer. “Why compare the flight of your bullet to a standard G1 or G7 projectile when you can use your own projectile as the standard?”

Throat Erosion, Part II

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The following is a specially-adapted excerpt from the forthcoming book “Top Grade Ammo” by Zediker Publishing. BuyZedikerBooks.com for more.

by Glen Zediker

We talked about rifle barrel throat erosion last time, in descriptive terms. Short course: It’s the area just ahead of the case neck area in a rifle chamber that bears the majority of the “flame cutting” effect of burning propellant gases. The wear in this area determines the accurate life of a barrel. The greatest detractor from accuracy is the roughness that results from the deteriorating steel surface. Of course, the throat is advancing, getting longer, at the same time. After time, the “jump” or gap the bullet has to leap before engaging the lands plays its part in poor on-target performance.

I’ve always followed a “scheduled” replacement plan on barrels, determined, of course, after much experimentation and many measurements. That’s for competition rifles. For others, I have a more-or-less “shoot it until it doesn’t shoot well” approach.

If you chronograph frequently enough, and are using the same load, you’ll see velocities drop as more rounds go through the barrel. This is because of the lengthening throat: more room for expanding gases, lower pressure, lower velocity. I know a few who gauge barrel replacements based around chronograph readings, and the resultant propellant charge adjustment necessary to maintain “new barrel” bullet speed. The general consensus, for a round with approximately .308 Win. case capacity, is 2.0gr. So when it takes another 2 grains of propellant to restore original velocity, that one’s done.

Here are a few more ideas on barrel life, and also a few thoughts on how to keep a barrel shooting better longer.

Last time I made a statement that I should have qualified more, but space is always such a concern in these articles. It was respecting the idea of pulling a barrel, cutting some off its chamber-end, and then rechambering it. This overwrites the eroded area, well most of it. That can only be done for a bolt-action rifle. I said that worked well for chromemoly barrels but not for stainless steel barrels, and the difference is in the “machine-ability” of the steels. It is possible to set back a stainless barrel, but it’s tough to have a

“chatterless” cut result. A little more usually needs to be removed to get good results with stainless, and this, of course, is making the barrel overall that much shorter. Certainly: you have to plan on a set-back at original barrel installation, and that means include enough extra length to compromise. Usually it takes a minimum of 1 inch to get a worthwhile result with chromemoly.

So what can reduce the effects or severity of erosion, which is only to say prolong the life of the barrel? Reasonable does of propellant behind lighter-weight bullets, that’s one. Another is that flat-base bullets do result in less cutting than boat-tails. Flat-base bullets “obturate” more quickly. Obturate means to “block,” but here it means to close a hole, which is a barrel bore, which means to seal it. The angled tail on a conventional boat-tails creates a sort of “nozzle” effect, directing gases to the steel surface. Can’t much be done about that, though, because when we need boat-tails we need them. However! A relatively obscure but well-proven boat-tail design does increase barrel life, and also tends to shoot better though a worn throat. A “rebated” boat-tail has a 90-degree step down from the bullet shank (body) to the tail. It steps down before the boat-tail taper is formed. These obturate fully and quickly. It is common for competitive .308 shooters to switch from the popular Sierra 190gr MatchKing to a Lapua 185 rebated boat-tail when accuracy starts to fall off due to throat wear. Sure enough, the Lapua brings it back for a couple hundred more rounds.

Some propellants burn lower temperatures than others. Some double-based propellants claim this, and, true, if you can be happy with the performance of one, it can extend barrel life a few hundred extra rounds. WW 748 is one of those propellants and my experience with it is that the claims are true. It’s not night-and-day, but there’s a difference. Research to find others.

Coated bullets don’t have any influence on throat erosion, but they tend to perform better though a rough throat. Boron-nitride is the only bullet coating I can recommend. I use it. Do an extra-good job cleaning the throat area in a wearing barrel. Copper and other residues tend to collect more as the steel gets rougher and rougher.

 

 

 

CCI Adds Quartet of New ‘Big 4’ Loads

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CCI Ammunition, the only American manufacturer of handgun shotshells, has introduced four all-new handgun shotshells, featuring larger shot. They are available in four popular handgun calibers, as listed below:

Description / MSRP
Big 4 9mm Luger / $17.95
Big 4 .38 Special – .357 Magnum / $14.95
Big 4 .44 Special – .44 Magnum / $19.95
Big 4 .45 Colt / $19.95

Shipments of this new product are being delivered to dealers.

Centerfire handgun shotshells have long proven themselves as highly practical options for close-range pests, and the new CCI Big 4 loads get their names from a payload of No. 4 lead shot, which provides extended range and better energy and patterns to take down larger pests at longer distances.

The No. 4 lead handgun shotshells are packed in reusable boxes of 10 shotshells.
The No. 4 lead handgun shotshells are packed in reusable boxes of 10 shotshells.

 

 

How Is 22 LR Ammunition Made?

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Have you ever wondered how .22 ammo was actually manufactured? Join 22Plinkster on a factory tour of CCI and Speer and see the process take shape:

Factors in Barrel Life: Throat Erosion Part I

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The preceding was a specially adapted excerpt from the book The Competitive AR15: the ultimate technical guide, by Glen Zediker and Zediker Publishing. Available at Midsouth Shooters or BuyZedikerBooks.com

By Glen Zediker

Last time the topic was finding the bullet seating depth that touches the lands or rifling. In discussing the tool featured, the Hornady LNL O.A.L. gage, I also mentioned how this appliance can also be used to document barrel throat erosion. A little more about this…

As rounds go through the barrel, one after another, the chamber throat is advancing, moving toward the muzzle. The “wear” in a barrel is all right in the throat. The influence is “flame cutting” by the high-temperature gases that result from burning propellant. The steel is burning up. At some point, it quits shooting well. The reason for a fall-off of accuracy is a combination of excessive free-bore (space between end of the chamber neck area and the first point of contact a bullet will have in the barrel) and also roughness, plain and simple. Bullets won’t enter the rifling as smoothly and the rough surface rips at the bullet jacket. Any wear along the remaining length of the barrel is insignificant, and not influential; it’s mostly from simple friction.

So how long does a barrel last? About 5 seconds. Let me explain.

Of course, that’s spread over a scant few milliseconds at a time over a number of rounds. There are two main influences in the progress of erosion: bullet weight and amount of propellant. The more of each, the faster the deterioration, but bullet weight factors mostly. As was introduced in the material way on back about gas port pressure, if we plot out pressure levels against bullet movement through the bore, we get a “pressure-time curve.” Pressure levels are associated with respective levels of flame cutting. A steep P-T curve (slow bullet acceleration) means more concentrated cutting over a shorter distance. It’s clear, then, that lighter bullets will do less damage than heavier bullets, even though the lighter bullets mean burning more propellant. In a .223 Rem., for example, a steady diet of 77-grain bullets will shorten barrel life compared to using mostly 55-grain bullets. Fortunately, .223 is one of the kindest to barrel steel of popular rounds. I expect about 5000 good rounds from a quality barrel (about the same as .308 Winchester). Some folks offer a much higher figure than that, but, again, “shoots well” is subjective. Shoot it until it doesn’t shoot well. The cartridge factors mightily: .243 Win.? Maybe 1200 rounds with 107-grain bullets.

Barrel steel material most definitely has an influence on life. Short answer: get stainless steel. Comparing true “match-grade” barrels, stainless will not shoot one bit better than chromemoly, but will shoot its best for longer, about 10-15 percent more accurate rounds. The reason is in how the steel “wears” as throat erosion progresses. Chromemoly tends to get rough (like sandpaper) whereas stainless steel tends to form cracks with still-smooth areas between them (like a dry lake bed). The stainless erosion is less disruptive to the bullet jacket.

However, that’s not a blanket recommendation of stainless. When a stainless barrel quits shooting, it quits right then and there. Accuracy fall-off is abrupt. Like in the middle of a string… Really. Chromemoly group sizes cone outward more slowly. Chromemoly tends to continue to shoot “better” after it’s lost its gilt-edge. Some will shoot a very long time at only a minimum fall-off from its best performance. I have to recommend chromemoly for a semi-auto, unless, that is, the semi-auto is strictly a competition rifle. Then, just take your medicine.

A bolt-gun can have its chromemoly barrel pulled and “set back” to prolong its life. Simple: cut a half-inch or so off the chamber-end of the barrel, rechamber it, back in business. Can’t do that with stainless. Of course, semi-automatics can’t get this treatment because of gas system orientation.

Chrome-lined barrels do, yes, tend to last longer (slower erosion), but they also tend not to shoot as well, ever. Steel hardness also factors, but most custom match barrels are made from pretty much the same stuff.

Back, finally, to using the gage: Take a measurement every now and again. Experience will tell you when. My standard is +0.150 inches, compared to the reading I got on the barrel when new. That’s a max. Sometimes they quit before then, sometimes not, but no matter how it’s shooting, I rebarrel at +0.150. I use stainless and I don’t want the next target to be when it quits. I’m a little conservative, by the way… Some very good shooters comfortably extend that to 0.250.

Keep a worn barrel clean! Scrub the throat area (carefully of course). The cracks and roughness attract and retain fouling. There are other “tricks” to help preserve accuracy for a longer time, and I’ll talk about those next time.

 

Use the Hornady LNL O.A.L. gage to record and then track barrel throat wear. This isn’t technically a “throat erosion gage,” which do exist, but the author has found it an easy and reliable way to keep up with an advancing throat. As the seating depth gets longer, it’s indicating how far the throat is advancing.
Use the Hornady LNL O.A.L. gage to record and then track barrel throat wear. This isn’t technically a “throat erosion gage,” which do exist, but the author has found it an easy and reliable way to keep up with an advancing throat. As the seating depth gets longer, it’s indicating how far the throat is advancing.

 

Bullet weight, mostly, determines barrel throat life. Why? The heavier the bullet, the slower it accelerates, and the more time the flame from burning propellant has to torch into the metal. Even though a lighter bullet is burning more propellant, it’s the intensity of the cutting that does the most damage.
Bullet weight, mostly, determines barrel throat life. Why? The heavier the bullet, the slower it accelerates, and the more time the flame from burning propellant has to torch into the metal. Even though a lighter bullet is burning more propellant, it’s the intensity of the cutting that does the most damage.

 

Stainless steel barrels keep their “gilt-edge” accuracy for about 15% more rounds, but hit the wall head-on and in a big way when they reach their limit. Chromemoly steel tends to open up groups sooner, but also maintains “decent” accuracy for a longer time, in the author’s experience — the groups open more slowly. Most are best served with chromemoly in a semi-auto.
Stainless steel barrels keep their “gilt-edge” accuracy for about 15% more rounds, but hit the wall head-on and in a big way when they reach their limit. Chromemoly steel tends to open up groups sooner, but also maintains “decent” accuracy for a longer time, in the author’s experience — the groups open more slowly. Most are best served with chromemoly in a semi-auto.