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

What's the best alternative chambering for a general purpose AR-15?

  • .300 Blackout

    Votes: 43 37.1%
  • 6.5 Grendel

    Votes: 16 13.8%
  • 6.8 SPC

    Votes: 6 5.2%
  • 7.62x39

    Votes: 29 25.0%
  • .450 Bushmaster

    Votes: 3 2.6%
  • .458 SOCOM

    Votes: 3 2.6%
  • .50 Beowulf

    Votes: 4 3.4%
  • Other (Specify in post)

    Votes: 12 10.3%

  • Total voters
    116
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.
 
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Took this guy with my 6ARC. 250 +/- with an 85 grain Lehigh Controlled Chaos. CMMG with a 16" barrel.

Just sayin
 

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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'.
 
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.
 
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.
 
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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.
 
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.:eek: (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!
 
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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.
 
I use other rifles. 30-06 and .308 are the only two I've used over my lifetime. I use bolt-action on buck only days, and semi-auto on doe days if we still need more meat. Now I'm going to need to go deer hunting.
Thanks.

edit: .308 rounds aren't expensive when you use one to three a deer season, and 3 at the range per trip for the tack drivers. Semi-auto I practice with milsurp, and do not count. 308 is easy to find milsurp.

I found the AK-47 Saiga sporting rifle in 308 with an eight round mag to be easily carried around, much easier than my tack drivers.
 
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Thank you, but I'm really not interested in purchasing a new Rifle chambered in .308 right now.
 
I don't know anyone who's tried to build an AR for 7 mm TCU (.223 necked up to 7mm), but the little cartridge has always interested me.

I was thinking about the 7mm Valkyrie.
If Lapua or Starline had brass available,
that might be worth investigating for the AR15.

The 224 Valkyrie looks interesting as well.
Add the 22 Nosler to the list. :D

At an indoor range, I asked the RO, what was making the building sound/feel like you're in the inside of a Timpani?
300 Blackout was his answer.

For a 458 SOCOM, this bullet might be interesting with an appropriate barrel length etc stc.
Pic below from Lyman's 49th.
 

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I don't know anyone who's tried to build an AR for 7 mm TCU (.223 necked up to 7mm), but the little cartridge has always interested me. I was thinking of picking up an H&R handi rifle and making a barrel for it, but then they went out of business.

If you want something you can buy factory ammo for, the .350 Legend would seem to be a good choice.

In re: vamint calibers. I once knew a gunsmith in NW PA who used to shoot groundhogs with a .458.

I used the 7mm TCU in a T/C Contender with a 14" barrel years ago. I'd have to review my old notes, but I think the OAL for this cartridge would be too long for use in an AR setup, unless the bullet was deeply seated. That might encroach on powder space enough to adversely affect ballistics. With the popular short AR barrels many shooters prefer, an additional velocity reduction would be guaranteed.

As I recall, with the Contender 14" barrel, I never quite reached published book velocities anyway. Quite accurate cartridge, though. Perhaps this has been done with the AR already, I don't know.
 
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Most of the poll choices would not be legal for deer in my state. I chose "other" as the 350 Legend seems to be catching on around here.
 
What's the best alternative chambering for a general purpose AR-15?

That is like asking what is best Chevy, Ford, Dodge (now Ram)?

I have a few ARs, 2 in 5.56/.223 and one in 9mm.
The only thing I use them for is punching holes in paper and maybe HD if ever needed.
The only other chambering I would consider is maybe a .22lr if I could be sure of a good reliable firearm. And they would be for punch holes in paper.

When it comes to varmint or big game I have other firearms that are better suited for said purpose.
 
Will add that the S&W upper in 5.45x39 sure is fun to shoot. 7N6M has a weird ammonia smell and the recoil impulse is next to nothing.
 
The longer barrels give the shooter a little more fps, ergo they shoot flatter. Is that a big deal? I dunno, I don't get out to shoot long range any more. Could be placebo or who knows what. The LR guys like the 6.5 with a 24 inch barrel better than the 20" and that better than 18", etc. I got my 6.5 made up with a 20 incher. Seems to be adequate for all around use. If I ever get out to LR again and can shoot "6's" with any regularity I'll be happy.
 
For hunting medium game and 2 legged lethality Im still partial to the 6.8SPC. A bolt, barrel and mags and youre in business. A 110gr hornady at 2550-2600fps is what the military wanted.
 
Can't believe I picked up a 2nd 300 BLACKOUT upper: what the HADES, it was Black Friday, after all...!:rolleyes:

Cheers!
 

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