Why don't I hear much about AR style rifles in .308?

[epijunkie67]

Whenever I read threads about battle rifles in .308 I usually see people talking about the M1A or CETME or the G3 (or similar) style rifle. I've never shot one of the ARs in .308 but wasn't that the round that Stoner originally designed the rifle around? Is there something wrong with them that people don't use them or shoot them enough to get a lot of word out about them?

Why don't I hear about them very much?

 

[jklinstein]

It's called an AR-10. I think they're on the expensive end of the spectrum, but supposedly the most able to be accurized. I hear about them quite often.

jacob

 

[LaEscopeta]

Well, the Marines are now using .308 AR-10s:

http://www.thehighroad.org/showthread.php?t=210866

.308 … wasn't that the round that Stoner originally designed the rifle around?

That’s what I’ve read, but that rifle (the original AR-10) lost in trials to the M-14, which the US Military adopted. Stoner and others at Armalite won the next round of trials with the .223 version of the AR-10, the AR-15 (adopted as the M-16 of course)

Armalite (after being sold several times) still makes and sells AR-10s:

http://www.armalite.com/sales/catalog/rifles/ar10t.htm

 

[OldSchooler]

May I make a little minor clarification? The 7.62 x 51 NATO round is different than the .308 and was originally designed around the .300 Savage, not the .30-06, as some believe. It's intent was to replace the .30-06 in service use, to be fitted to shorter actions. It's real difference is that it has reduced chamber pressures over the .308 WCF and near duplicate ballistics to the old Savage cartridge. The .300 Savage had been a deer buster for decades up til that time and was a wise choice any way you look at it. Still is, any way you look at it.

Shortly after the work began, the NATO group nations began calling for a reduced caliber, high velocity round with similar range to the 30 caliber rounds. We were to develop it, naturally, and they would all standardize on it - a "joint" effort if ever there was one. I can only imagine that they had begun to take note of the COMBLOC .30 Russian round (7.62x39) and wanted to incorporate some its attributes, while besting it in range.

The US, on the other hand, pushed for the .30 cal round, as that had been our proven standard for half a century, and we put it up in the M14. Excellent rifle, albeit heavy and ponderous at nearly 10 lbs unloaded. The M14 didnt last, but the cartridge remains in service to this day, albeit not in general issue form, being the purvue of the long range rifleman - 'snipers' if you will. {Putting the round up in a variant of the AR series makes so much sense, that I wonder why it took so long. I mean we had that in the M-14 from the beginning. Now every field unit can have long range power shooters in the group...talk about your supression fire! But then I am not up on current developments...}

But our partner nations wanted no part of the .30 cal and pressed for something "lighter." In fact, according to some of my research recently, it was the BELGIANS who offered the defining parameters for the new cartridge, at least in part. The tactics of warfare had changed during WWII and the Korean Police Action, and the desire to offer the infantryman more mobility, firepower and lighter weight had kicked in - and is still with us today in the 5.56 NATO round. Being only a student of such things, I cant say thats a bad thing, either...

 

[DMK]

I've never shot one of the ARs in .308 but wasn't that the round that Stoner originally designed the rifle around?

Yes, the original Armalite AR-10 was chambered in 7.62x51 and was the father of the AR-15/M16. It was put in the service rifle contract competition (as the T-47?) against test a version of the M14 known as the T-44 and a test varient of the FAL known as the T-48. Obviously, the T-44 was chosen the winner and became the M-14, the successor U.S. service rifle to the Garand.

Being a design ahead of it's time, the original AR-10 did have a number of problems during the service rifle tests. It was at a very early stage of development,had a number of inventive, advanced concepts in design and still needed some bugs worked out(in all probability these problems would have been worked out in production as they were with the M16). The modern .308/7.62x51 versions (including the current AR-10B, on the other hand, are developments of (children of) the mature and modern AR-15/M16 designs and have proven to be very good rifles.

One of original AR-10 varients

 

[Nightcrawler]

They're not all that common. Up until Armalite started making commercial AR-10s, there were practically none available. Few countries ever adopted the AR-10.

Even then, for a long time there were only two options. The AR-10 and the Knight's SR-25. Basically an expensive gun and a very very expensive gun. Compared to the prices for FAL, M14, and G3 clones, well...they didn't take off. The AWB also hurt the .308 ARs, as AR-10 20 round magazines were outrageously expensive in the ban years, and were difficult to find.

Many AR-10s are reportedly too tight for a general service rifle. Accurate, yes, but not as reliable as other types.

Nowadays, you have more options. Bushmaster has discontinued its BAR-10, which was an AR-10 clone designed to use FAL magazines. It just didn't work all that well. Rock River Arms is trying to get it to work now, maybe they'll have better luck. DPMS has its recent line of LR-308 rifles, and they've gotten good reviews (though again, even the "service" type carbine has been reported as too tight to run with surplus ammo). Armalite continues to make is AR-10 rifles, though they take different magazines than the Knights and DPMS guns.

So, you'll see more in future. Outside of what I've typed, I can't recommend any specific model or brand.

 

[BCHunter]

7.62 NATO ARs

The 7.62 X 51 NATO, as far as a boots on the ground infantry combat rifle, is an abject failure. The US demanded a 30 calibre round when most other NATO nations desired a smaller diameter round, ranging from .276 down to 6mm (.24). The NATO round and rifles chambered for it were developed in answer to the AR type rifle, the Maschinepistol “MP” 44, the German military used, mainly in their Eastern Front operations, the 7.92 X 33 KURTZ. This rifle and round were so effective that Mikhail Timofeevich Kalashnikov probably used this rifle and round as a base model for his superb AK47, arguably the best assault rifle in the world.

The development of the 7.62 NATO round and the rifles designed to handle it were both heavier and longer than the AK and recoiled a lot harder. The ammunition was much heavier than the 7.62x39mm round, weight relation to how much a trooper can carry, and offered no real ballistic advantage. The 7.62 NATO round was discarded shortly after entering combat for a much shorter, smaller diameter round, the now 5.56 X 45 NATO. The 7.62 X 51 NATO round lasted only just over a decade as a main line infantry rifle round, approximately the same amount of time the 30-40 Krag lasted.

The 7.62 X 51 NATO was arguably not an effective machine gun round in its original form, but has developed into an adequate MG round having a slightly larger diameter chamber and higher operating pressures than the commercial “twin” the 308 Winchester. Don’t use this ammunition in your .308 Win.

As specialised military use, such as sniper rifles, the 7.62 X 51NATO is an accurate and effective round.

ARs chambered in the 7.62X 51 NATO are only civilian novelties as far as general combat riles are concerned.

 

[Nightcrawler]

The 7.62 X 51 NATO round lasted only just over a decade as a main line infantry rifle round, approximately the same amount of time the 30-40 Krag lasted.

For the US, yes. Most of NATO used it for much longer.

The 7.62 X 51 NATO was arguably not an effective machine gun round in its original form, but has developed into an adequate MG round having a slightly larger diameter chamber and higher operating pressures than the commercial “twin” the 308 Winchester. Don’t use this ammunition in your .308 Win.

Exactly what changes have they made to the M47 ball round in the last 40 years that have made it go from an "ineffective" to an "adequate" machine gun round? It's prettymuch always been a 147-150 grain spitzer at 2700-2800 feet per second.

 

[Deer Hunter]

I've used 7.62 NATO in my old Remintgon 700, no adverse effects.

And even in that little lightweight gun, the recoil for me is not there. And that's in a 6 pound gun. I would assume that our soldiers can handle a 7.62 NATO rather easily. DSA makes a tactical carbine FAL system that, in my opinion, would work great as a military weapon.

The 7.62 NATO isn't "too much" for practical use.

 

[Father Knows Best]

Um, the 7.62x51 NATO doesn't offer any ballistic advantage over the 7.62x39 Russian? What are you smoking? The 7.62x51 is a full power rifle cartridge, while the 7.62x39 is an intermediate. The 7.62 NATO throws a heavier bullet than the 7.62 Russian (150 grains vs. 123 grains), and at much higher velocities (typically 2800 fps vs. 2300 fps).

The 7.62 NATO offered huge ballistic advantages over the 7.62 Russian, and still does. It's also not too much for the average soldier to handle. It is really the same cartridge (ballistically) as the .30-06 but in a shorter case. Our soldiers had no problems handling the .30-06 in 2+ wars, so I don't think they suddenly would have had a problem handling it in the 1950s and 1960s.

The main "problem" with the 7.62 NATO was that it is too powerful for use in light, fully automatic weapons. It isn't controllable by most people in a shoulder-fired automatic weapon rifle weighing around 10 pounds or less. Since combat doctrine in the 1950s and 1960s was moving toward the use of full auto from shoulder fired weapons, a lighter recoiling cartridge was needed. The close range combat typical of southeast asia also meant that the longer range of the 7.62 NATO and other full power rifle cartridges wasn't needed by the average grunt.

The 7.62 NATO is still ballistically far superior to the 7.62x39 Russian, and is perfectly capable of being handled by average soldiers provided they aren't trying to fire full auto from the shoulder. That's why even the M14s in use today typically have had full auto capability removed.

 

[rbernie]

7.62 NATO round ... was much heavier than the 7.62x39mm round, weight relation to how much a trooper can carry, and offered no real ballistic advantage.

Well, uh, pretty much no. The 7.62x51 NATO round has significantly more energy at any range and a much flatter trajectory than the M43 cartridge, and only weighs about twenty percent more.

The 7.62 X 51 NATO .... having a slightly larger diameter chamber and higher operating pressures than the commercial “twin” the 308 Winchester.

Well, uh, pretty much no. The 308 commercial round operates at HIGHER pressures than the NATO variant. The NATO variant was downloaded slightly to help NATO member countries like Spain convert their older arsenal stocks to a shared round without having to throw all of their old rifles away. The NATO spec for 7.62x51 has a max pressure of 50,000 PSI, whereas SAAMI specs for 308 max out at 62,000 PSI.

You are correct in that the .308 Win chamber is somewhat smaller than a 7.62 x 51 mm chamber.

Having said all of this, and to get the thread back on track - I just picked up a used-but-well-cared-for Armalite AR10 (20" flattop) a couple of weeks ago, and so far I'm loving it. It's been 100% reliable thru a couple of hundred rounds of commercial 308 and handloaded 308 hunting rounds so far. I've got beaucoup SA battlepacks on order; we'll see how well it does on MilSurp as soon as they come in.

In stock form, the AR10 is a little heavy (the bolt carrier must weight 24 oz.!) and it appears to be overgassed if the weight of the BCA and the seriously heavy rating on the recoil spring are any indications. I've installed a regulator'ed gas tube and a softer recoil spring; that's made the rifle cycle with much less drama and helps it handle/feel more like its smaller AR15 brother. All it needs now is a Jard trigger and it'll be ready for the next hog/deer hunt.

Accuracy with my 308 hunting loads has been superb - just over MOA but uniformly less than 1.5" five shot groups at 100 yards off a sandbag rest.

 

[yhtomit]

Trying to understand the .308 v. The 7.62 X 51 question

rbernie's post above (and the one to which he repsonded in writing it) unfortunately confused me even more on this issue.

If I buy a military-style rifle in .308, can I safely fire NATO 7.62 X 51 in it? What about the converse? (Are any rifles of general availability to U.S. civilians even chambered in 7.62 X 51?)

My naive previous understanding was the difference was only in nomenclature; I can see that that's not the case, but the practical upshot is still eluding me. If the chambering for the 7.62 X 51 is slightly bigger, will that cartridge even fit (safely) into a .308 rifle? (At least one of the responses here basically says "Yes" to that question. Is the difference just so slight that it all comes out in the wash?) If the specs for the .308 mean it can have a *higher* pressure than the military cartridge, and if 7.62 X 51 will indeed fit guns labeled .308, then ... is there really a problem?

My only longarm at the moment is a .22 rifle, but I would one day -- after defeating my anticipated grad-school debt -- like to get a rifle in a larger caliber, and I like the idea of one that can shoot 7.62 X 51 / .308 (to the degree they are interchangeable, as per my above questions ) because I'd rather only have guns with ammo that's in at least somewhat common military usage (so I could buy military surplus for reasonable prices, and because it's unlikely to be hard to find around the U.S., at least right until the heat-death of society ...).

So, I apologize for asking about something which the previous posts seem to address, but I'd really appreciate a dummy-level walk-through of the practical upshot. (And if anyone's up to that challenge, how about the .223 v. 5.56 × 45 mm ... I understand it's a similar case of "not entirely interchangeable.") What's important to me is that I don't make decisions based on a misunderstanding of the facts, in partcular a dangerous one.

Cheers,

timothy

 

[rbernie]

If I buy a military-style rifle in .308, can I safely fire NATO 7.62 X 51 in it?

Absolutely yes.

What about the converse?

Generally, but not always. For example, it's pretty well established that Ishy 2A's and CETMEs and converted Spanish Mausers are not robust enough to live on a steady diet of hot commercial 308 loads. That's not to say that you can't or shouldn't shoot 308 in an Ishy 2A or CETME - just that you risk overstressing the rifle if you don't shoot 308 loads in moderation.

Other than these three examples, I know of no other rifles chambered in 7.62x51 that are not recommended to be used with commercial 308 on a steady basis.

 

[MachIVshooter]

I have both an AR-10A2 carbine and a Century G-3 and I regularly run commercial .308 and 7.62 nato through both of them. I have never had a problem. The only thing i don't do with these is push my luck with warm handloads. As a policy, I never run my own hot stuff through autoloading rifles.

Most of the time, I run Federal American Eagle through them, as it is good ammo that is fairly inexpensive. It happens to be the only ammo that reliably produces sub-MOA groups from the G-3. My AR-10 is generally 2-4" groups @ 100 yards, but I am running a 4 MOA red dot so this is expected. Armalite rates them at 1.5-2 MOA, and I bet it would do at least that well with proper optics.

The AR has run 100% with all factory ammo and has only balked at the 180 grain SP handloads.

 

[BCHunter]

308 Win compability with 7.62 NATO

I think you really need to read what I said.

The chambering on an MG M60(some) & M240 has a slightly larger chambering (not bore) than the commercial 308 Winchester and is designed to operate at higher pressures (67,000 as opposed to 60,000 maximum for commercial and military shoulder arms). This is because the military 7.62 X 51 NATO in its original form was grossly inadequate as a MG round. 7.62 X 51 NATO ammo designed for shoulder arm use is safe for use in commercial 308 Winchester arms. Commercial 308 Winchester ammo can cause a lit of problems when used in a medium MG chambered for 7.62 X 51 NATO.

I ain’t smoking anything Father Doesn’t Know Anything. For general combat use, and that is what I was talking about (get with the program before you shoot your mouth off), the 7.62 X 51 NATO offers no ballistic advantage over the 7.62 X 39 round commonly chambered in the AK47. It was realised by many nations in the 30’s that combat actually happened at somewhat less than 300 Meters and so cartridges like the 30-06, 8mm Mauser (7.92 X 57), 303 British and others were vastly overpowered for warfare, but at the commencement of WWII starting all nations went to war with what they had for a general purpose combat shoulder arm. That is why the Germans developed the MP 44 and the 7.92 KURTZ. By the way Father Doesn’t Know Best the US has a habit of choosing grossly over powered small arms (like the 7.62 X 51 NATO) and paying for it in the long run, aside from the 30-06 there is the 45 Auto Colt, which by the way is not now being used, why?? Because the 9mm is so much more effective considering actual combat circumstances involving side arms. Combat and civilian/police use are very different. Why the heck to you think the US forces in Vietnam discarded the M14 for the M16?

The 308 Winchester (7.62 X 51 NATO) is an absolutely excellent cartridge in sporting, specialised military and tactical purposes. It is an extremely accurate round and can handle most big game on the North American continent with ease I have owned many such chambered arms and have used surplus and military supplied ammo by the case for plinking and serious target shooting. I have reloaded those cases with no problem with excellent results. My warning was about ammunition designed for medium MG use. It is loaded at higher pressures than commercial rounds and has a thicker neck. It’s probably safe in commercial arms made by the major manufactures, quality custom houses and gunsmiths, but it is note worth to understand it is NOT the same as commercial ammunition. If in doubt why risk it?

 

[OldSchooler]

If I buy a military-style rifle in .308, can I safely fire NATO 7.62 X 51 in it?
If you mean a commercial firearm of recent manufacture, then yes, as a rule.

What about the converse?
It isnt recommended, as a rule.

It has to do with pressures in the chamber and varying headspace and throat dimensions.

Typical pressures for the two rounds are like this (approximate):
.308 WCF: 60,000+ cup's (about 62,000 +/-)
7.62x51 NATO 50,000+ cup's (about 53,000 +/-)

As a round destined for use by mulit-national forces, there can be no absolute guarantee that each and every make of firearm designed for the cartridge will adhere to the same stringent parameters. In fact, military rifles in general are known to vary widely in the critical dimensions mentioned, to allow for just what we are talking about - variances in both ammo and weapon tolerances.
Thus it was widely decided to maintain lower pressures in the NATO round than one finds in commercial grade hunting ammo.

If you want a comparable round, say for reference or reloading, look to the .300 Savage - the progenitor of the original .30 caliber "T" cartridge.

Too, while many older military rifles like the Spanish Mausers and some of the Enfields have been converted to 7.62 NATO, it is widely accepted that they are not of sufficient strength in either material or lock up to methods to accept the .308 in it's full house form, as already mentioned.

To read about it in detail, here's alink:
http://www.surplusrifle.com/shooting2006/308vs762nato/index.asp

Are any rifles of general availability to U.S. civilians even chambered in 7.62 X 51?
Yes. Milsurp rifles in the caliber abound and, of course, commercial rifles chambered for .308 WCF will accomodate the NATO round.

 

[rbernie]

The chambering on an MG M60(some) & M240 has a slightly larger chambering (not bore) than the commercial 308 Winchester and is designed to operate at higher pressures (67,000 as opposed to 60,000 maximum for commercial and military shoulder arms).

I'm curious where you got the data that indicated that linked ball ammo (M80) or M61/62 rounds were loaded ANY differently in terms of pressure than the same rounds loaded on strippers or loose-packed. Based on my readings of the US DoD TMs and FMs, it's all loaded to the same spec, with 67,000psi being the proof load and not the operating load.

 

[Shrinkmd]

So opinion on Armalite AR-10A2?

Compared to a Bushmaster A2 XM15 E2S 20"m rifle, how does the Armalite stack up? Does anyone out there own/shoot both? I'm interested in the cheap 7.62 on AIM right now, it would be cheaper to shoot the armalite than the .223 stuff, right?

Ah, no excuses needed for wanting to buy another rifle

 

[Bottom Gun]

My Eagle Arms AR10 has served me quite well. It is extremely accurate and reliable. I used it to take my elk three years ago.

It was designed to shoot pointed bullets and may not be reliable with flat point, round nose, or some hollow points.
I load Nosler Partition bullets for hunting big game and Hornady SST for deer. It has been 100% reliable with them.
I also load my hunting rounds hot. Full power .308 loads don’t faze this rifle.

I use a lot of surplus ammo in it. It has done well with everything I have used in it. I have used Lake City, Portuguese, South African and Australian ball.

They are pricier than some AR-15’s but well worth the money. I would, however, avoid muzzle brakes. Recoil is not bad since it is a fairly heavy rifle. If you have a brake on one of these, you will have to hunt with ear protection and you won’t make many friends at the range when you touch it off beside them.

I had a second upper with a stainless barrel with brake and found the plain barrel shoots more accurately. I couldn’t tell any difference in recoil between the two. I ended up selling the upper with the brake.

These are very nice rifles. If you find a good deal on one, grab it.

 

[BCHunter]

Chamber difference

http://www3.sympatico.ca/shooters/7_62vs308.htm



Why?? Pressures may be too high using military ammo.

Let's say we have a brand new .308 Winchester rifle with a minimum headspace chamber. It measures at 1.630". We find a deal on some Mil-Surp 7.62x51mm NATO ammo & go to the range. Ammo that averages at 1.6315" will be a very, very tight fit in a 1.630" chambered rifle. Too tight in fact. If you are able to chamber the cartridge you will have higher than normal pressures. Given a few other variables this could result in redlining the chamber pressure & having the rifle self disassemble a few inches from your face. If it's an autoloader then there's a real good chance you'll have a slam fire (where the cartridge fires as the bolt lock up without any desire for it to do so on your part) or an out of battery fire (where the cartridge fires before the bolt is locked) which will cause a self disassembling firearm to materialize in your hands. .0015" is a very big deal when you lack that much space


http://carnival.saysuncle.com/002453.html



I can show you dozens of sites like these, but I just picked a couple out quickly.

Unless you are a seasoned reloader and at least a gun savvy able to recognise problems with high pressure loads, rounds not properly chambering, or squib load problems why risk your firearm, eyesight or worse? I have refused to stand beside or around shooters, both rifle and shotgun, who are shooting obviously faulty loads, either hand loads or “factory round which usually turn out to be military surplus”, before and will probably do so in the future.

 

[Crosshair]

BCHunter PLEASE change the color of your text. That bright blue is just impossible to read.

 

[Wes Janson]

aside from the 30-06 there is the 45 Auto Colt, which by the way is not now being used, why?? Because the 9mm is so much more effective considering actual combat circumstances involving side arms.

I kinda stopped reading there. There's a fair amount of evidence out there on why we switched from .45 ACP to 9mm Parabellum. I don't believe all the hype in the magazines about the 9mm being an abject failure in Iraq, but the idea that the .45 ACP is "too much" for a sidearm is ridiculous.

 

[NineseveN]

I ain’t smoking anything Father Doesn’t Know Anything. For general combat use, and that is what I was talking about (get with the program before you shoot your mouth off), the 7.62 X 51 NATO offers no ballistic advantage over the 7.62 X 39 round commonly chambered in the AK47. It was realised by many nations in the 30’s that combat actually happened at somewhat less than 300 Meters and so cartridges like the 30-06, 8mm Mauser (7.92 X 57), 303 British and others were vastly overpowered for warfare, but at the commencement of WWII starting all nations went to war with what they had for a general purpose combat shoulder arm. That is why the Germans developed the MP 44 and the 7.92 KURTZ

First, I'd lose the bad attitude, we like t see people stick around, but insulting folks just isn't going to be very conducive to your stay here.

Going on to your point, you used the term, "no ballistic advantage"...care to provide data where 7.62 Russian short outperforms 7.62 NATO? Perhaps you meant, 'no real world advantage" or 'no practical advantage'? In terms of ballistics, scientifically, the 7.62 NATO round is by far the better performer at any range. For suppression fire, the military .308 is probably a bit much in terms of recoil, but that in no way changes how it performs in terms of ballistics.

By the way Father Doesn’t Know Best

Come on man, cut that out, will ya?

the US has a habit of choosing grossly over powered small arms (like the 7.62 X 51 NATO)

Hmmm, plenty of soldiers that kept their M14's against orders in Vietnam, and plenty that are asking for them in the sandbox now, as well as those that grabbed AK-47's in both conflicts might have something to say about that. If anything, we saw a trend in the US military to settle on inferior, smaller calibers due to their lack of wanting to properly train soldiers in the art of the rifle and instead deciding to just call for suppression fire (which didn't work out and ended up costing so much in ammunition that they removed the full-auto selector for the M16's).

and paying for it in the long run, aside from the 30-06 there is the 45 Auto Colt, which by the way is not now being used, why?? Because the 9mm is so much more effective considering actual combat circumstances involving side arms. Combat and civilian/police use are very different.

There are indeed .45ACP's in use, just not by general ground forces. The operators that get to choose, don't normally choose 9mm. However, in terms of terminal performance, there is very little difference between any service caliber handgun cartridge overall, so the point is moot.

Why the heck to you think the US forces in Vietnam discarded the M14 for the M16?

Political decision that forced them to is the way history reads.

 

[NineseveN]

As for why we don't hear a lot about the .308 AR's, not many of them out there being made in the past ten years, those that were made were expensive and took insanely expensive magazines as compared to the other available .308 military rifles...hopefully that all changes with the offerings from DPMS and Rock River.

I want an LAR-10 to go with my FAL.

 

[BrockB]

I have shot a few AR-10s but don't own one (yet!), I really want to put a LAR-10 through the paces to see what it could do. I like RRA AR-15s so I'm sure that the 308 is just as nice.