What's the best alternative to 5.56 for an AR-15?

[Well Armed]

The 7.62x39 case head is close to the limit for the standard AR15/M16 bolt head. So far mine hasn’t failed, but I did buy a spare.

A year or so back I saw a 7.62x39 built on the AR10 “platform” and I was intrigued by it. As far as I know nothing has be released commercially. But I think it would make an interesting rifle.

There isn't usually a problem with ot need to change the bolt. The bolt is usually fine. The problems come with the extractor if the extractor and other components aren't setup correctly. The issue also has more to do with using steel cased ammo with the extractor. Brase is fine and there should be no worries. I also had not had any issues whatsoever with my setups regardless. It's not something I worry about.

 

[Wyo]

I voted for the 6.8 SPC mostly because I have several AR’s in that caliber. It’s superior to the 5.56 for defensive use and I’ve used it on quite a few mule deer, antelope and hogs. Never had to shoot one more than once and never lost one. I prefer something bigger for elk but I know of several that have been taken with the 6.8 with premium bullets. It’s better at long ranges than the 7.62x39. I handload for it so cost of ammo isn’t a concern. All in all, if I had just one alternative cartridge for the AR it would be the 6.8 for me. As an aside, and speaking of hunting with AR’s, I’ve been doing that for years. I also use full size mags not because I need them but because I can, unlike in most less-free states. I’ve taken mule deer and antelope with 5.56 loads using the 64 gr. Powerpoint and the 62 gr. Nosler bonded bullet. Again, no problem but I pick the shots pretty carefully. I’ve also used the M1A, an LMT-MWS and an FAL in .308, again, because I can. I figure we Americans have lots of choices so I try to take full advantage of that!

 

[shawn mccarver]

Sorry, but stay with 5.56 in your AR or M4. If you want another readily available rifle cartridge that can do double duty for defense, then get the 7.62 x 39 or the .308 Winchester. Once you decide on the cartridge, then pick the rifle. If you use an AR-10 for the .308, best make certain the model selected uses the Magpul magazine. Nothing much wrong with the M1A in that caliber. If you pick the Russian cartridge, be careful of the AR platform as most will simply not play nice with the AK magazine. A notable exception is the SIG Neuhausen 553R, but it is really difficult to get. The new Colt in 7.62 x 39 has supposedly solved the issues, but I have no personal experience with the rifle. I think Ruger still makes the Mini 30, and it works.

 

[rockquarry]

I voted for the 6.8 SPC mostly because I have several AR’s in that caliber. It’s superior to the 5.56 for defensive use and I’ve used it on quite a few mule deer, antelope and hogs. Never had to shoot one more than once and never lost one. I prefer something bigger for elk but I know of several that have been taken with the 6.8 with premium bullets. It’s better at long ranges than the 7.62x39. I handload for it so cost of ammo isn’t a concern. All in all, if I had just one alternative cartridge for the AR it would be the 6.8 for me. As an aside, and speaking of hunting with AR’s, I’ve been doing that for years. I also use full size mags not because I need them but because I can, unlike in most less-free states. I’ve taken mule deer and antelope with 5.56 loads using the 64 gr. Powerpoint and the 62 gr. Nosler bonded bullet. Again, no problem but I pick the shots pretty carefully. I’ve also used the M1A, an LMT-MWS and an FAL in .308, again, because I can. I figure we Americans have lots of choices so I try to take full advantage of that!

I did some work with the 64 Power Point and the Nosler Bonded several years ago along with many other .22 bullets. Neither of these shot well in comparison with other bullets in the same weight range. Accuracy would be minimally adequate for hunting if the distance wasn't great. In an AR that shot accurately, I got five-shot groups of 1 3/4" at 100 yards and 1 1/2" in a CZ that was capable of half-inch groups with good bullets.

I'd have to dig out old notes to see exactly what the Power Points did, but I think accuracy was a bit worse than the Nosler Bonded. I've read other reports of mediocre to poor accuracy with both bullets. Can you fill me in on your experience with these bullets as far as accuracy? Thank you for your comments-

 

[hardluk1]

neather the 300blk or 7.62x39 have useful ballistics for a quick clean kill shot on game beyond 150 yards . The heavier sub sonic loads don't even manage 1000 ft lbs at 100 yards . I would hate to watch a find deer standing in a field on on a woods road have not real chance at a well places shot at 200 yards . Understand too the 30 cal version both like a different barrel twist for the sub sonic loads than they do for the lighter hunting loads but that can depend on what some concider ok for accuracy too .

The 6.5 grendel still has the heavier 123gr hunting ammo with over 1000ft lbs of energy at 400 yards and most others manage that at 300 yards and being able to make that longer shot does matters for many of us .

 

[rockquarry]

neather the 300blk or 7.62x39 have useful ballistics for a quick clean kill shot on game beyond 150 yards . The heavier sub sonic loads don't even manage 1000 ft lbs at 100 yards . I would hate to watch a find deer standing in a field on on a woods road have not real chance at a well places shot at 200 yards . Understand too the 30 cal version both like a different barrel twist for the sub sonic loads than they do for the lighter hunting loads but that can depend on what some concider ok for accuracy too .

The 6.5 grendel still has the heavier 123gr hunting ammo with over 1000ft lbs of energy at 400 yards and most others manage that at 300 yards and being able to make that longer shot does matters for many of us .

About thirty years ago, while deer hunting, I had an opportunity for a 200 yard shot, an unusually long distance where I hunted at the time. I was carrying a Ruger 77MKII (limited production gun made for Davidsons) in 7.62x39. I don't recall the load I was using, but I had done much load development with many soft point bullets up to 130 grains loaded to max or near max. Still inadequate for humane shots on any game at 200 yards.

I never carried that rifle for hunting again. Foolishly, I was using a minimal deer cartridge that would generally work fine with proper shot placement if the range been considerably shorter. Don't put yourself at such a disadvantage. Use a rifle or carbine chambered for a cartridge that will work well and work humanely in all circumstances.

It's also important to remember the significant velocity loss when using guns with very short barrels like those of 16" or so. Why these are popular for general use is a mystery to me. Performance suffers accordingly, apparently a fact many are unaware of.

 

[Wyo]

I did some work with the 64 Power Point and the Nosler Bonded several years ago along with many other .22 bullets. Neither of these shot well in comparison with other bullets in the same weight range. Accuracy would be minimally adequate for hunting if the distance wasn't great. In an AR that shot accurately, I got five-shot groups of 1 3/4" at 100 yards and 1 1/2" in a CZ that was capable of half-inch groups with good bullets.

I'd have to dig out old notes to see exactly what the Power Points did, but I think accuracy was a bit worse than the Nosler Bonded. I've read other reports of mediocre to poor accuracy with both bullets. Can you fill me in on your experience with these bullets as far as accuracy? Thank you for your comments-

The Powerpoint load was factory and the Nosler bullet was handloaded. Neither would have been good enough for 300 yd. prairie dog shooting but they were fine for bigger game. The Winchester load did 1” to 1 1/2”. The Nosler stayed closer to an even inch in the AR, and I pretty much limited shots to about 150 yds. or less. Both bullets performed well, mostly penetrating fully at those distances. It was apparent that both expanded well. All in all, I was well satisfied with both bullets.

 

[Echo40]

Okay, so question for the folks who voted for 6.5 Grendel: is it true that in needs a barrel length of at least 20" to really reap the benefits or is that just a lot of nonsense?

 

[LittleAugieMo]

Meh..."two is one/one is none" buy a complete .308 short bbl ar platform

 

[jaguargolf]

Polar bears have Been taken with 5.56 AR’s

I hunt with one in 6.5 Grendel.

Recoil setup in AR is easy on my right retina that has become detached in past.

 

[rockquarry]

The Powerpoint load was factory and the Nosler bullet was handloaded. Neither would have been good enough for 300 yd. prairie dog shooting but they were fine for bigger game. The Winchester load did 1” to 1 1/2”. The Nosler stayed closer to an even inch in the AR, and I pretty much limited shots to about 150 yds. or less. Both bullets performed well, mostly penetrating fully at those distances. It was apparent that both expanded well. All in all, I was well satisfied with both bullets.

I doubt I'd ever use a .22 centerfire for game, but an excellent bullet advertised as a game bullet that will shoot far more accurately than the mentioned Winchester Power Point and Nosler Bond is the the 65 gr. Sierra Game King. Of course, the 65 GK probably costs more than the others, but an accurate bullet is worth the cost.

I've shot groups with this bullet to 200 yards, at which distance it is as accurate as the 69 Sierra Match King target bullet.

 

[IAM Rand]

Took this guy with my 6ARC. 250 +/- with an 85 grain Lehigh Controlled Chaos. CMMG with a 16" barrel.

Just sayin

 

[BabaBlueJay]

I am more of an AR-10 guy, so I voted for the venerable 308, it will drop nearly anything you need to drop.

 

[rwsmith]

Yep, I noticed.....

Do you really think most of these mutts pay attention to an opening tread , nope .

The OP did say ar15 that most seem to not pay attention too and just run off on there personal preference . Still for the OP to ask what cartridge to use on a AR15 he has to be a newbie or he would have never ask .

I just assumed he meant AR-15 'platform'.

 

[Echo40]

I honestly had to check and make sure that an AR-15 lower couldn't somehow accept .308 via some sort of staggered magazine after receiving so many posts telling me to get a .308.

I suppose that I should have just said that I was looking strictly for Complete Uppers to pair with my M&P15, but I honestly wasn't expecting many folks to suggest that I just go out and buy an AR-10.

If I had $1000+ to spend on an AR-10, then I probably would go that route, but that's not the case. Specifically, I'm looking at inexpensive Complete Lowers for the AR-15, stuff that's like ⅓ that price.

 

[Well Armed]

I honestly had to check and make sure that an AR-15 lower couldn't somehow accept .308 via some sort of staggered magazine after receiving so many posts telling me to get a .308.

I suppose that I should have just said that I was looking strictly for Complete Uppers to pair with my M&P15, but I honestly wasn't expecting many folks to suggest that I just go out and buy an AR-10.

If I had $1000+ to spend on an AR-10, then I probably would go that route, but that's not the case. Specifically, I'm looking at inexpensive Complete Lowers for the AR-15, stuff that's like ⅓ that price.

308 ammo is expensive and a lot of the other more boutique ammo is you inquired about. Next, you stated you aren't really buying for hunting and long ranch 300+ yard shooting on game, so it's kind of a moot point that the other members are bringing up and focusing on. The choicd for the most affordable to shoot rounds that will take out most North American predators that may attack you as well as be ideal for CQB and self-defense are squarely between super sonic 300blk and 7.62x39.

Some, not all, other members seems more intent pushing you towards what they like and what works best for their needs while not taking all of your needs and concerns into account.

FYI: I own 308 battles rifles, e.i, AR10, a couple of 308 AK47s, and a couple Cetme G3 variants in 308. I rarely shoot them because it's overkill for any practical application I'd need, the rifles tend to be much heavier (AR10 included), and I don’t want to spend $20 +/- over 20 round magazine I fire within less than a minute.

 

[Echo40]

Well, seeing as .300 BO and 7.62x39 have been leading the polls since the start, it seems that the majority of those who voted in this thread are of the same mindset. Sure, 6.5 Grendel is in 3rd place and Other — which I presume is what the .308 crowd voted — is in 4th, but by a rather substantial amount of votes.

Currently, I'm thinking 7.62x39 might be the one to go with, since the unique magazines would solve the problem with having to keep magazines seperate to avoid the potentially catastrophic risk of chambering a .300 BO in a 5.56 Upper. Besides, I've found an M4 Profile 7.62x39 Upper that strikes my fancy that's currently on sale. So if I don't find anything better by Black Friday or someone manages to sway me in another direction, that will be what I go with.

 

[STORMINORMAN]

Please note CAPITOLIZED corrections to my original post: SORRY!

Uh, 30 caliber bullets don't readily "chamber" very well in a 5.56 barrel:
(THIS IS WAY INCORRECT: SOME WILL CHAMBER!) the reverse is also (ACTUALLY, 5.56 SHOULD NOT BE ABLE TO CHAMBER IN A 300 BLACKOUT BARREL: BRASS IS TOO LONG) true... Usually only catastrophic with slam fires. (NOPE: IF A 300 BLACKOUT ROUND SHOULD ACCIDENTLY CHAMBER AND IS FIRED THERE WILL BE HELL TO PAY!) Not a good thing in a defensive situation. (THIS, UNFORTUNATELY, IS TRUE!)

Perhaps that is why there are many, many different magazines available? Color coded, 20 vs. 30, etc.

Cheers!

P.S. Now, putting a 357 SIG round through a 40 S&W barrel is a whole 'nother "kettle of fish"! Accuracy really SUCKS!

 

[Echo40]

I dunno, I just read a bunch of articles which stated that certain .300 BO rounds could be chambered in a 5.56 Upper and thus there were risks involved.

 

[STORMINORMAN]

I dunno, I just read a bunch of articles which stated that certain .300 BO rounds could be chambered in a 5.56 Upper and thus there were risks involved.

You are correct and I have edited my post: thanks!