Tag Archives: 308 Winchester

RELOADERS CORNER: 5 Simple Steps To M1A Reloading Success

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The M14/M1A can be a cantankerous beast to reload for, so follow these suggestions to tame it down. Keep reading…

M14 match shooter

Glen Zediker

The “5 steps to success” are at the end of this article… First, read about why they will matter as much as they do!

A couple times back I decided that the best topic to write about might be the most current, and I defined that by the most recent questions I fielded on a topic. As the assumption goes: they can’t be the only ones with that question… So, over this weekend I had a series of questions from different people all on the topic of reloading for the M1A, the civilian version of the military M14.

Now. Since the M14 was the issue rifle of choice for a good number of years, and without a doubt the (previously at least) favored platform for the various-branch military shooting team efforts, it went through some serious modifications to best suit it to that very narrow-use objective: High Power Rifle competition. Although the M14 hadn’t been routinely issued to most troops for decades, it was still going strong in this venue. That changed in the mid-90s when Rules changes boosted the AR15 platform to prominence, and soon after, dominance.

Match conditioning an M14 involved modifications to virtually every system component, and resulted in a fine shooting rifle. Very fine. Amazingly fine. The one mod that prodded the impetus to write all this next was the barrel chambering specification changes. A while back I went on about what 7.62 NATO is compared to its fraternal twin .308 Winchester.

Match-spec M14 chambers are decidedly NOT NATO! They’re .308 Winchester, pretty much. I say “pretty much” because they’re on the minimum side, dimensionally, compared to SAAMI commercial guidelines for .308 Win. Lemmeesplain: the true “match” M14 chamber is short, in throat and in headspace. The reason is ammunition bound. I’ll explain that too: Lake City Match ammo was and is a universal competition cartridge. Military teams compete in, well, military team competitions. Some are open to civilians, some are not. All, however, used issued ammo across the board. You were given your boxes of Lake City Match, or Special Ball, or one of a couple other same-spec variants, prior to the show and that’s what you used for the event. Everyone used the same ammo. Civilian or Service. There were exceptions, like long-range specialty events, but what was said held true the vast majority of the time. That meant that everyone wanted the same well-proven chamber, civilians too.

Lake City Match ammo
Back in the day… Here’s what you got, which was the same as what everyone else got, for a DCM (now CMP Inc.) rifle tournament. “Here ya go son, and good luck…” and since we took as much luck out of the equation as possible, we all used a rifle chamber in our M14s and M1As that maximized Lake City Match ammo performance. And that’s why I’m writing all this…

Given this, that’s why a “match” M1A chamber is different than a SAAMI. It was built to maximize Lake City Match accuracy. That’s a short round. The headspace is a few thousandths under what’s common on a chamber based around commercial .308 brass. 1.630-inch cartridge headspace height is regarded as minimum for commercial.

Headspace reading Lake City Match
The true M14/M1A match chamber is a short chamber: headspace is very tight. That’s because Lake City Match ammo is short. Compare this to what you might want to use, and if you have a genuine match chamber, best make sure the ammo fits… Measure both the results of sizing operations and also any new ammo or brass before you fire it in one of these chambers! I have encountered commercial .308 Win. rounds that were too long out of the box (cartridge case headspace dimensions). Here’s a cartridge headspace read on a Lake City Match compared to a commercial Winchester match load (inset) I had on hand. Read taken with a zeroed Hornady LNL gage. And NEVER fire commercial ammo intended for hunting use; the component mix and round structure is almost certain to be wrong.

Check out  headspace gages  at Midsouth HERE

So sizing a case to fit a match M1A, especially if it’s a hard-skinned mil-spec case, takes some crunch. To compound difficulty, M1As and M14s unlock very (very) quickly during firing. The bolt is trying to unlock when the case is still expanded against the chamber walls. The little bit of space this creates results in a “false” headspace gage reading on the spent case. It’s going to measure a little longer than the chamber is actually cut. That can lead someone to do the usual math (comparing new case and spent case headspace reads) and end up with a “size-to” figure that’s too tall, that has the shoulder too high. For instance, let’s say the spent case measured 1.634 and the new case measured 1.627, indicating 0.006 expansion or growth. Given the usual advice (from me at least) to reduce fired case shoulder height by 0.004 (semi-autos) for safe and reliable reuse would net a size-to dimension of 1.630. But. There can easily be a “missed” 0.002-0.003 inches resultant from the additional expansion explained earlier. My advice for a match-chambered M1A is to reduce the fired case all the way back down to the new case dimension. That might sound like a lot, and it might sound excessive, and it might be — but, it’s the proven way to keep this gun running surely and safely. That, however, is not always an easy chore. Some mil-spec brass is reluctant to cooperate. And, by the way, don’t kid yourself about reducing case life. This gun eats brass; I put just three loads through a case before canning it.

M14 gas system
These rifles have an overactive gas system that tends to create premature bolt unlocking, and this leads to excessive case expansion. I recommend resetting the fired case headspace to match a new case reading for safety’s sake.

Two helps: one is to use petroleum-based case lube, like Forster Case Lube or Redding/Imperial Sizing Wax. And size each case twice! That’s right: run each one fully into the die twice. Double-sizing sure seems to result in more correct and more consistent after-sizing headspace readings.

A “small-base” sizing die (reduced case head diameter) is not necessary to refit match brass into a match chamber. It might help using brass that was first-fired in a chamber with more generous diameter, but sized diameter isn’t really the “small” part of the M1A match chamber. Again, the small part is the headspace.

Forster National Match dies
A Forster “National Match” die set is a guaranteed way to ensure adequate sizing for an M1A match chamber. This sizing die has additional shoulder “crunch” built in, and that’s the “National Match” part: it essentially replicates Lake City Match ammo dimensions.

Take a look at these dies HERE

So that’s the source the problem reloading for this rifle. And, again, “this rifle” is an M1A with a true mil-match armorer’s spec chamber. We best make sure that our sized cases are going to fit the chamber, plus a couple thousandths clearance for function and safety. And safety mostly. M1As are notorious for “slam-fires” which happen when the free-floating firing pin taps the primer on a chambering round delivering sufficient intrusion to detonate. Impressive explosions result. If the case shoulder is stopping against the chamber before the bolt can lock over, that can be all the pin needs to maximize the effect of its inertia.

Speaking of, there are three sources and fortunately the same number of cures for slam-fires. One, first, is the correct sizing on setting back the case shoulder so the shoulder doesn’t stop against its receptacle in the chamber. Next is making sure there are no “high” primers; each primer should be seated at least 0.005 inches under flush with the case head. Next, and very important: primer composition, which equates to primer brand. Do not use a “sensitive” primer, one with a thinner, softer skin. Although they are great performers, Federal 205 are too sensitive for this rifle. Better are WW, CCI 200.

My thoughts
I don’t like this chamber… I also used one because I competed in events with issued ammo. I don’t recommend a “true” M14 chamber because that’s a NATO. Plain old standard .308 Win. specs work better and allow more flexibility in ammo and component selection. Even though the true mil-spec match chambers are not common, the reason I’ve written as much as I have on this topic over the years is because a mistake can be disastrous. One of the folks who wrote me one question shared a story about a friend who blew up his match M1A firing improper commercially-loaded ammo through it. Whoa.

A CASE FOR THE M1A
This gun needs a stout case. They won’t last long no matter what but they might not last at all if they’re too soft. I’ve broken some new commercial cases on one firing. Thicker/thinner isn’t the issue: it’s the hardness of the alloy. Harder material better resists reaction to the additional stress of premature system operation. New-condition mil-spec cases are great, if you can get them. Next best is Lake City Match that was fired in a match-chambered rifle. Stay completely away from anything, and everything, fired through a NATO-spec chamber. It’s nigh on not possible to size them enough to suit. For me, WW is the only commercial case I will run through my M1A. They’re thin, but pretty hard.

308 components
Here’s a full component set I recommend, and use, for true match chambered M1As.

I did a whole chapter solely on reloading for the M14/M1A for my book Handloading for Competition that didn’t get printed into it for various reasons. However! I have the entire chapter available as a PDF download on my website. Get it HERE

And for even more info on reloading for the  M1A, order the new book Top-Grade Ammo, available here at Midsouth. For more information on this book, and others, plus articles and information for download, visit ZedikerPublishing.com

 

M14 loading dos/donts

RELOADERS CORNER: Barrel Twist Rate

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Understanding the relationship between bullets and barrel twist helps prevent mistakes. Here’s what you need to know…

Glen Zediker

Sierra 90gr MatchKing

Why am I devoting this space this time to such a topic? Well, because it’s commonly asked about, and, no doubt, because it influences some of the decisions and options faced in choosing the best-performing load for our needs. Making a mistake in choosing twist can limit both the selection and performance in the range of usable bullet weights and styles.

First, barrel twist rate is a component in the architecture of the barrel lands and grooves. The lands and grooves form a spiral, a twist, that imparts spin to a bullet, and the rate of twist is expressed in terms of how far in inches a bullet travels to make one full rotation. “1-10” (one-in-ten) for example means “one full rotation for each ten inches of travel.”

Bullet length, not weight, determines how much rotation is necessary for stability. Twist rate suggestions, though, are most usually given with respect to bullet weight, but that’s more of a generality for convenience’s sake, I think. The reason is that with the introduction of higher-ballistic-coefficient bullet designs, which are longer than conventional forms, it is easily possible to have two same-weight bullets that won’t both stabilize from the same twist rate.

70gr VLD
Good example: 70-grain VLD (left) needs an 8; the Sierra 69-grain MatchKing next to it does fine with a 9. It’s bullet length that determines the needed twist, not just weight.

The M-16/AR15 barrel changes give a good example. Short history of mil-spec twist rates: Originally it was a 1-12, which was pretty standard for .224-caliber varminting-type rounds, like .222 Remington, which were near-universally running bullet weights either 52- or 55-grain. That worked with the 55-grain FMJ ammo issued then. Later came the SS109 63-grain round, with a bullet that was a bit much for a 1-12. The military solution was total overkill: 1-7. That’s a very fast twist.

Commercially, the 1-9 twist became the standard for .223 Remington for years. It’s still popular, but is being replaced, as far as I can tell, by the 1-8. An increasingly wider selection of barrels are done up in this twist rate. I approve.

1-8 twist.
Generally, well, always actually, I recommend erring toward the faster side of a barrel twist decision. 8 is becoming a “new standard” for .224 caliber, replacing 9 in the process. Reason is that new bullets tend to be bigger rather than smaller. Don’t let a too-slow twist limit your capacity to exploit the promise of better long-range performance.

I’d always rather have a twist too fast than not fast enough. For a .223 Rem. 1-9 is not fast enough for anything longer than a routine 68-70-grain “magazine bullet,” like a Sierra 69gr MatchKing. 1-8 will stabilize any of the newer heavier bullets intended for magazine-box cartridge overall lengths, like a Sierra 77gr MatchKing. An 8 twist will also shoot most of the longer, higher-BC profiles, like the Sierra 80gr MatchKing (which is not intended to be assembled into a round that’s loaded down into a magazine).

Other popular calibers have likewise edged toward faster and faster “standard” twist rates, and that includes 6mm and .308. Once those were commonly found as 1-10 and 1-12, respectively, but now there’s more 1-7s and 1-9s offered. Reason is predictable: longer and heavier bullets, and mostly longer, have likewise become more commonly used in chamberings like .308 Winchester and 6XC.

The tell-tale for an unstable (wobbling or tumbling) bullet is an oblong hole in the target paper, a “keyhole,” and that means the bullet contacted the target at some attitude other than nose-first.

Base your next barrel twist rate decision on the longest, heaviest bullets you choose to use, and at the same time realize that the rate chosen has limited those choices. If the longest, heaviest bullet you’ll shoot (ever) is a 55-grain .224, then there’s honestly no reason not to use a 1-12. Likewise true for .308-caliber: unless you’re going over 200-grain bullet weight, a 1-10 will perform perfectly well. A rate that is a good deal too fast to suit a particular bullet may cause damage to that bullet (core/jacket integrity issues), and I have seen that happen with very light .224 bullets, like 45-grain, fired through, say, a 1-7 twist. At the least, with that great a mismatch you might not get the velocity up where it could be.

.224 bullet extremes
Clearly, these don’t need the same barrel twist to attain stability: the bigger bullet needs double the twist rate that will fully stabilize the smaller one. There’s quite an extreme range of .224-caliber bullets, like this 35-grain varmint bullet and 90-grain match bullet. Now. Do not fire the little bullet in the big bullet’s barrel! It probably would not make it to the target… Swap barrels and bullets and the big one will likely hit sideways.

Bullet speed and barrel length have an influence on bullet stability, and a higher muzzle velocity through a longer tube will bring on more effect from the twist, but it’s a little too edgy if a particular bullet stabilizes only when running maximum velocity. My failed 90-grain .224 experiment is a good example of that: I could get them asleep in a 1-7 twist 25-inch barrel, which was chambered in .22 PPC, but could not get them stablized in a 20-inch 1-7 .223 Rem. The answer always is to get a twist that’s correct.

Effects on the load itself? Yes, a little at least. There is a tad amount more pressure from a faster-twist barrel using the same load, and the reason is initial bullet acceleration is slower.

The preceding was adapted from Glen’s newest book, Top-Grade Ammo, available here at Midsouth. For more information on this book, and others, plus articles and information for download, visit ZedikerPublishing.com

At the Range with Springfield Armory’s SOCOM 16

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By Robert A Sadowski

Prior to the 2016 SHOT Show, I was shipped Springfield Armory’s SOCOM 16 Model AA9611PK rifle. In the spirit of full disclosure, I’ll admit that I am a fan of the M1A platform. My only complaints are the fixed stock and heavy weight. The new AA9611PK not only addresses these issues, it does it in a way we modern shooters expect. We expect to be able to customize our rifles with aftermarket parts. We expect a variety of sight and optic choices. We expect a lot, and the new SOCOM 16 delivers.

The Springfield Armory SOCOM 16 Model AA9611PK is a semiautomatic long-stroke piston design. It had a 16.25-inch barrel with 1:11-inch twist. Overall, it measured 35.5 to 38.5 inches in length and weighed 9.3 pounds empty.
The Springfield Armory SOCOM 16 Model AA9611PK is a semiautomatic long-stroke piston design. It had a
16.25-inch barrel with 1:11-inch twist. Overall, it measured 35.5 to 38.5 inches in length and weighed 9.3 pounds empty.

Old-school M14 dudes might wince at the non-traditional pistol-grip stock. It is an Archangel chassis that not only trims the weight of the SOCOM, it also trims the overall length. The exterior is flat-black polymer. At the shoulder end is a five-position adjustable CQB buttstock. Part of the issue with the M1A was the fixed stock.

For some shooters kitted up with gear or wearing heavy clothing, the rifle was difficult to fire comfortably. The adjustable stock not only alleviates that situation, it also fits the rifle to a variety of shooter statures. It also features a rubber buttpad and a cheek riser. The cheek riser helps get a solid cheekweld on the stock, which is important for long-range shooting, and you will soon see what the platform is capable of out to 100 yards.

If you want to swap out the stock, you can choose any other aftermarket AR stock. The rear of the chassis is built like a buffer tube. There is no denying that the pistol grip is atypical, and no doubt it is comfortable to shoot. The Archangel pistol grip flares out at the bottom and is serrated on the front and rear straps for plenty of hold when the SOCOM starts barking. It also has a storage compartment for batteries and small tools.

The perforated muzzlebrake helps reduce muzzle rise and keep you focused on the target when shooting fast.
The perforated muzzlebrake helps reduce muzzle rise and keep you focused on the target when shooting fast.

The stock will take any aftermarket AK grip—another plus for shooters who like to customize their gear. The stock has three Picatinny rails attached, two three-slot rails on either side of the forend and one seven-slot on the bottom. Want to add vertical grips, a tactical light, or laser? The new SOCOM can. The magazine well is also a gaping mouth ready to suck in magazines. It ships with a 10-round magazine but is compatible with five- and 20-round mags.

The iron sights on the SOCOM 16 have always been top-notch, adjustable, enlarged military aperture with front tritium. It has a forward rail to mount a magnified, long-eye-relief, scout-style scope. This SOCOM 16 also has a Vortex Venom red dot reflex sight that uses a Springfield Armory clip guide mount, which places the red dot at the perfect height and distance while not interfering when the rotary bolt ejects empty brass. At 25 yards offhand, the red dot was fast and accurate. The perforated muzzlebrake tamed the recoil and muzzle rise. I easily smashed a few magazines of clay pigeons like I had been shooting the rifle for years. Distance, though, is the key.

The five-position stock means the SOCOM 16 can be adjusted to fit your stature and the gear or clothing you are wearing.
The five-position stock means the SOCOM 16 can be adjusted to fit your stature and the gear or clothing you are wearing.

With an assortment of .308 Winchester cartridges—Hornady Steel Match 155-grain BTHP, Black Hills Gold 168-grain A-MAX and Hornady Match 178-grain BTHP—I put the SOCOM 16 through its paces using a rest. Though aiming a red dot at 100 yards is not exactly precision shooting, at 50 yards and under the 3-MOA dot offers fast, accurate shooting. At 100 yards, the dot is large. I assumed at 100 yards I’d experience different results. The 3 MOA placed on an 8-inch target provided a nice sight picture, a red center with a black donut outside edge.

The Hornady Steel Match 155-grain BTHPs delivered 2,400 fps and shot 1.5-inch groups (three shots) at 100 yards. Black Hills Gold 168-grain A-MAX rounds produced 2,440 fps and 2.25-inch average groups at 100 yards. Hornady Match 178-grain BTHPs hit 2,390 fps at the muzzle and shot 2.5-inch average groups at the test distance.

With the rifle adjusted to me, it all came down to trigger work. The SOCOM 16 has a two-stage military trigger. After taking up the light first stage, the second stage proved to be nice with about a 5½-pound pull weight. The rifle was comfortable to shoot. Nice.

The new SOCOM 16 offers an out-of-the-box rifle ready for defense work or hunting. I can’t think of a better round and setup for feral pigs, deer, or black bears. The adjustable stock means it’s easier and more convenient to take in and out of a vehicle and store. The sight package is a nice setup. The SOCOM 16 adapts to how you want to shoot and the situation you are in and does it with a level of modularity and customization not seen previously in the M1A platform.

Robert Sadowski has written about firearms and hunting for nearly 15 years. He is the author of four gun books, editor of three others and is a contributor to numerous gun-enthusiast magazines, including Combat Handguns, Black Guns, Tactical Weapons for Military and Police, Gun Tests, Personal and Home Defense, Gun Hunter, SHOT Business, and others. He has a personal affinity for large-caliber revolvers and the AR platform.

Barnes Offers New VOR-TX Ammunition and Component Offerings

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Barnes Bullets has added three loads to the VOR-TX ammunition lineup and new 300AAC Blackout and 450 Bushmaster components for handloaders.

The VOR-TX line extensions will bring three new loads to the Barnes VOR-TX family: A 308 Win. load featuring the 130-grain TTSX bullet, a 300 Winchester Magnum load with a new 190-grain LRX bullet, optimized for long-range performance, and a 35 Whelen load featuring the Barnes TTSX 200-grain projectile.

Click here to see our stock of Barnes VOR-TX ammunition and to check to see when the new loads are in stock.

For handloaders who want to fine-tune and optimize their 300 AAC Blackout and 450 Bushmaster ammunition, Barnes will now offer the 300 AAC BLK 120 grain TAC-TX BT bullet, previously only available in VOR-TX ammunition, as a separate item.

Also available for the first time, Barnes will offer a 275-grain TSX FB bullet specifically designed for 450 Bushmaster platforms.

Click here to see our stock of Barnes bullets and to check when the new bullets are in stock.

Barnes Bullets 300 AAC BLK 120 grain TAC-TX BT
Barnes 300 AAC BLK 120 grain TAC-TX BT
Barnes Bullets 275-grain TSX FB Bullet 450 Bushmaster
Barnes Bullets 275-grain TSX FB Bullet 450 Bushmaster
Barnes Bullets 300 Winchester Magnum 190-grain LRX BT
Barnes Bullets 300 Winchester Magnum 190-grain LRX BT