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Most versatile AR15 caliber?

  • .17

    Votes: 0 0.0%
  • .20

    Votes: 0 0.0%
  • .224

    Votes: 11 11.5%
  • .243

    Votes: 23 24.0%
  • .257

    Votes: 3 3.1%
  • .264

    Votes: 10 10.4%
  • .277

    Votes: 44 45.8%
  • .284

    Votes: 1 1.0%
  • .308

    Votes: 9 9.4%

Most versatile AR15 caliber poll

6K views 24 replies 13 participants last post by  constructor 
#1 · (Edited)
What do you think is the most versatile caliber, not specific cartridge. Why do you choose that caliber? Also which base cartridge(case) do you think is better and why?

I know ...lots of different uses. It's multiple choice.
I'll start off saying I think the 6mm is because it'll kill paper, small varmints like pdogs, larger varmints, yotes and other predators and deer and hogs and IMO that is the range most hunt.
Case, the 6.8 case as a base because I think the Grendel size case is too large for the bolt and mags.

Yes I made a mistake .223" should have been .224"
 
#5 ·
I'm with you on the 6mm. .243 has long been one of my favorites. I looked at the 6x45 several years ago before deciding on the 6.8 but I passed because it goes against my sense of logic. I don't care for cats that are necked up, only down. Just don't seem right to me.
 
#6 ·
I agree with woodstock.
6mm does everything the 224 does and more in a very simple portfolio.
You have varmint bullets, match and some pretty decent assortment of hunting where the
223 might fall on the light side for hogs and larger deer.
The 257 is a nice one but the bullet assortment is too small and somewhat exclusive. Ballistically talking
doesn't do anything to differentiate/outperform from the 6mm and then there you have amazing bullet choices.
I think anything larger than the 277-7mm is hard to get more performance in the small AR.
Only when you hit the 35 caliber start to see some other possibilities.
The 30 and 338 calibers do not make much sense on the small AR.
I don't think it is a matter of opinion. If we study options pragmatically, physics dictate what happens with the limited real state.
 
#8 ·
I don't think it is a matter of opinion.
For the record, I did vote 6mm. I agree that 6mm in an AR15 platform covers most of the bases very well. The ability to run a variety of bullet designs in a wide array of weights, to me, makes the 6mm the clear choice.

However, some may include the ability to run subsonic as criteria in their decision. In this case, your choice begins in the .277+ range. Many apparently consider the versatility of subsonic performance high on their list (based on the sales of the 300BLK).

So while I agree with your vote, I think it actually is a matter of the user's definition of versatility.
 
#7 ·
I voted 308 thinking this was an all inclusive large/small frame question before reading the OP's comments. So scratch 1 from the 308 tally.

I don't have much experience with most of these rounds out of a small frame AR15. I use a CZ527 22 hornet for ground hogs and coyotes, I would not swap to an AR unless I moved to a different part of the country with different varmints. I'm really impressed with .277 out of the 6.8 so far, and glad I recently built the rifle. But most versatile in the manner the op is talking maybe not.

Voted to quick. I was thinking shooting game from hogs to elk, or target shooting out to 1000 yards, along with being reliable out of any size AR. 6.5 would be the answer if it was a bolt gun, but seems to suffer more reliability issues in the large ar platforms versus 308. So that's why I chose 308 initially thinking 308 Winchester, and not 300 BO.
 
#11 ·
I agree with Harrison. The .243/6mm is the "MOST" versatile. Believe me I love my 5.56 and my 6.8 spc. Now I think most of the people that voted for the .277 on this sight are biased. 6mm bullets available from 55 to 115 grains. That pretty much covers the versatility needed for me. Put that in a 6.8 spc case and ya baby now we are having fun.
 
#13 ·
When you think about it the 6mm would make the perfect service round based on either a slightly fattened 5.56 case or the 6.8 case in 6mm, even better.
There are folks that would say a larger caliber would benefit in PDW platform but when you look at the numbers at 100 yards of popular bullets like
lets say a 6mm 85grains there is no such benefit at impact and in shorter distances or CQB is irrelevant because they all have plenty of power to spare.
Also the extra SD in smaller bullets at faster or even the same speeds is potentially a better penetrator in hard barrier for tactical use.
The 6x45 is so easy and forgiving to reload that I believe one could piss inside a case and get submoa results. The only issue with the 6x45 is that the standard
reamers do not put the ideal freebore. Once you reamed .030 to .050" of extra freebore the 6x45 can be pumped nicely with 85gr-90gr bullets to be
loaded nicely below 2.3". And one has the 6TCU too that yields some nice extra performance. It also outperforms the 25x45 from the same case.
Considering they are so easy and 6mm assortment of bullets including value packs are withing the same virtual budget as 223 this is a no brainer
for someone who shoots a lot. Inexpensive or virtually free brass, plentiful and affordable bullets and a 25%-30% extra terminal performance w/o
doing much.
At the same time the 6mm based on the 6.8 case is another great round. It doesn't have to be complicated and it can be esily done with either
a shorter 6mm hagar or 6mm WASP.
I am convinced simple cats attract more people than complex ones. Once you get into case cutting, complex case forming and/or fireforming more
people loose interest due to the extra work.

Simple is good.

Less becomes more in the end.
 
#14 ·
I voted 6mm as well and would like to build a 6x45 or Mongoose for my kids ar to hunt with purely for the cheap brass that I have a bunch of. I just want a flat shooting round that will work for game and varmints at less than 300 yds. Also contemplating doing a SBR off the .223 case.
 
#17 ·
Most versatile AR-15 caliber...

A strong case can be made for 6mm/243 for a number of reasons:
- wide range of bullet weights
- easy to tune for accuracy
- paper, varmint, predators. Neck shots on Deer & Hogs work perfect - but have not seen sufficient knock down if bullet misses CNS.
My choice in this caliber is Harrisons ARP 6BRX. I do not have a 6mm Mongoose - or 6/6.8 yet...
--
Another strong case, and my vote, is 6.8/277:
- again has a wide range of usable bullet weights
- still easy to tune for accuracy - but 6mm has the edge here
- varmint, predators, and I believe 6.8 has the upper hand for Deer & Hogs. Shots on hogs that fail to find the CNS normally will anchor the animal for a second shot.
- .277 Wolverine, 6.8, and 270AR are steps to increasing bullet performance. I understand some do not enjoy the work needed to build 270AR cases from Lapua brass, but just like spending money - you normally get what you pay for.. in this case a very strong performing round in 6.8/270.
--
-My 6.5 BRX is a close third for performance/accuracy and killing power. Using 6mm BR Lapua, BRX case forming is not difficult at all - but many folks will not take the time / effort to build BRX's - too bad really.

I also use 22 Hellcat and 257 Bobcat rounds based on 6.5x47 Lapua, but see these as niche calibers. Very high performance and accuracy, but not for everyone.

358 MGP is super easy to build, neck up 6.8 brass to 358, and run 180 or 200 grn bullets.

Lots of very usable options, and Your choice, but still believe versatility remains with 6.8/270AR.

Dennis
 
#19 ·
A strong case can be made for 6mm/243 for a number of reasons:
- wide range of bullet weights
- easy to tune for accuracy
- paper, varmint, predators. Neck shots on Deer & Hogs work perfect - but have not seen sufficient knock down if bullet misses CNS.
My choice in this caliber is Harrisons ARP 6BRX. I do not have a 6mm Mongoose - or 6/6.8 yet...
--
Another strong case, and my vote, is 6.8/277:
- again has a wide range of usable bullet weights
- still easy to tune for accuracy - but 6mm has the edge here
- varmint, predators, and I believe 6.8 has the upper hand for Deer & Hogs. Shots on hogs that fail to find the CNS normally will anchor the animal for a second shot.
- .277 Wolverine, 6.8, and 270AR are steps to increasing bullet performance. I understand some do not enjoy the work needed to build 270AR cases from Lapua brass, but just like spending money - you normally get what you pay for.. in this case a very strong performing round in 6.8/270.
--
-My 6.5 BRX is a close third for performance/accuracy and killing power. Using 6mm BR Lapua, BRX case forming is not difficult at all - but many folks will not take the time / effort to build BRX's - too bad really.

I also use 22 Hellcat and 257 Bobcat rounds based on 6.5x47 Lapua, but see these as niche calibers. Very high performance and accuracy, but not for everyone.

358 MGP is super easy to build, neck up 6.8 brass to 358, and run 180 or 200 grn bullets.

Lots of very usable options, and Your choice, but still believe versatility remains with 6.8/270AR.

Dennis
I agree with you. the BR case is an amazing case for many projects but in reality the expensive brass, annealing, forming/fire-forming deters a lot of people.
Here we have a lot of good and experienced reloaders but we also should think about the rookies and beginners who are easier to get engaged with something simple.
Anything with plentiful brass, plentiful bolts, and good affordable bullets and powders that is also easy to form is going to attract more people.

One of the reasons I built the 35 gunner was the simplicity of it and the other to be able to shoot pistol bullets. Just got a few thousand 200gr tmj bullets to shoot
at 12cents a piece. This for something that delivers a punch at 300 yards as an AK at the muzzle.
Perhaps not for everyone but just to say there are clear distinctive advantages and things I cannot achieve with other rounds and for the same cost x round.

If there are not clear advantages then it becomes just one more cats. I know.... I also have to control myself! ...the addiction is strong! lol.
 
#20 · (Edited)
Unfortunately the .473 diameter cases have been dropped from my choices due to the patent troll from vegas. The profits made from products relating to that case size would not pay for a court battle.

There are easy cats and tougher cats and no doubt most will choose the easy cats. Some don't even want to trim cases...
I've read enough articles to assume .224, 6mm and 30 cals are the most popular for different purposes.

For the AR15 the 6.8 is tough to beat for the main use of ARs which IMO is deer and hogs. Plenty of choices of bullets in the correct usable weight range and good velocity especially when handloaded 56-58k psi. Good factory ammo exist and soon CBB will produce high performance ammo that will definitely help the 6.8 when compared to the other choices.

Anyway this is about cats. The 224 and 6mm Predators are easy cats, no trimming just simple neck downs that anyone can handle. They are very accurate, perfect for targets and hunting. Guys that like and use the Grendel will probably go that route because of the common case.

The 6.8 cats are a little tougher due to the longer case. In order to use longer high BC bullets the case must be trimmed. Those that use the 6.8 case may be more inclined to go with a cat based on the 6.8 and that is what I am working toward. I like the 30 Herrett, it doesn't have the huge selection of usable bullets that the 6.8 does but enough to find one that works well. The Herrett hits hard, not sure exactly why the sound is so much different but even being as deaf as I am it's an impressive sound. One other thing I like, the cases work well out of the mag if Pmags or metal and the bolts are stronger than the Grendel bolts making it reliable enough for duty use. It would be my choice if I needed a CQB rifle.
The poll confirmed what I thought about a 6mm based on a 6.8 case. It would work on everything from small varmints to deer and hogs if need be. Now that the 6mm barrels have proven accurate I may finally move forward on a 6mm in a 6.8 case.

Thanks for taking time to vote and comment.
 
#22 ·
Harrison, I like your thinking!
 
#23 ·
Wise thinking.
1:8 twist in 6mm in a 6.8 case should do very well and not too different than the 6mmBR that must
be one of the most accurate and efficient calibers ever devised.
With a thinner case, smooth angle shoulder and popular bolts, is much better for autoloaders IMO.
A WASP or short hagar make it easy to get rolling with reamers and cut dies if needed but
I would stay away from the 30 degree angle in the shoulder and keep it simple.

6mm Back-Out... So simple even a caveman could do it. lol

 
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