Need Ideas - AR In Caliber Greater than .223

[kev74]

I'm in the early stages of an AR build (so far just lower parts on hand) and am looking for some ideas for caliber. I want something bigger than .223, but don't want to step up to AR10.

I'm going with a Thordsen stock and a non threaded barrel. I'd like something that would be practical for deer. I'm thinking that if I can use regular AR mags and bolt would keep things simple. I reload, so oddball calibers aren't a deal breaker. The longest I'm likely to shoot will be 200 yards at the range.

Any ideas and reasons are appreciated.

 

[meketrefe]

i am going to assume you want more power. Best all around caliber is the 6.8 for a simple one. If you want more power than 223 yet use the 223 brass, the 6x45 or 6tcu are very good 6mm if you reload. 6x45 ammo can be found but not easy.
The 458 socom will give big holes in shotgun trajectories.
Or if you want 308 power from a ar15 build one 35 gunner.

 

[Magnus]

HI JACK! I'm building two new ones. One in .223 for the wife, and one in unknown caliber. I already have a .223 and 300 blackout. 300 is another option for you, I've only test shot the 300 to make sure it worked I haven't gotten a chance to really see what it can do.

 

[ManrisFrack]

... so oddball calibers aren't a deal breaker...

How oddball are you looking to get? There are several wildcats that were designed to fit into an AR-15 but you are going to be converting brass for them. I'm building one in 30 Herrett AR and I've got a barrel for 270AR. There's several more (including meke's 35 Gunner) but I'll let you find them on your own if you decide to investigate the wildcat rabbit hole.

Best somewhat mainstream deer killers are 6.8 SPC and 6.5 Grendel but both require different mags and bolts. I've got a 6.8 and have taken two mature bucks with it so far.

There's also the .277 Wolverine. It's kind of an in-between because loaded ammo is available from a few small reloading companies but it doesn't have widespread adoption. It's just a barrel change and uses 5.56 as the parent brass like the 300 BO. It's faster and tends to carry more energy farther than the BO though. It also takes advantage of the quality selection of hunting bullets that the 6.8 has available.

 

[dsdmmat]

450 bushmaster?

 

[meketrefe]

Perhaps this will help you decide.

This is what you find in this list.....

A) Cartrige Name.
B) Rifle or Pistol Round?
C) What Bolt does it use? 223R and 6.8Bolts are the strongest. I put AK for the 7.62x39 but only a few manufactures make quality strong ones for these cartriges.
That is what I use in the gunner. 308W means the same diameter bolt face but still AR15. Some are for low pressure and cannot take much heat like the 458 socom or bushmaster.
The strong 308w bolt faces for the AR15 are pretty hard to find. WSSM is proprietary bolt and carrier group like the 30 RAR that is pretty much dying courtesy of remington.
D) What magazines can use. 223R-M means a modified version of it.
E) Is ammo available if one doesn't reload? 0=No, 1=Some, 2= Plentiful or at least reasonable assortment.
F) Does it give a performance improvement at 100 yards in terms of speed and/or energy vs. the 223? Power or speed at the muzzle are meaningless.

I am sure I missed quite a few but these should cover the most popular commercial and wildcats.


AR15 Calibers Type Tried Bolt Magazines Ammo 100Yard
10mm Pistol N 10mm 10mm 2 No
20 Practical Rifle Y 223R 223R 0 Yes
204 Ruger Rifle N 223R 223R 2 Yes
222 rem Rifle N 223R 223R 2 No
223 AI Rifle Y 223R 223R 0 Yes
223 Remington Rifle Y 223R 223R 2 NA
223x42 Rifle Y 68spc 68spc 0 Yes
25 WSSM Rifle N WSSM WSSM 1 Yes
25x45 Rifle N 223R 223R 1 Yes
30 BR Rifle N 308W AK&6.8 0 Yes
30 BRX Rifle N 308W AK&6.8 0 Yes
30 Remington AR Rifle Y 308plus 223R-M 1 Yes
300 OSSM Rifle N WSSM WSSM 1 Yes
300Whisper/Blackout Rifle Y 223R 223R 2 No
30-68 Herret Rifle Y 68spc 68spc-M 0 Yes
35 AR Gunner Rifle Y AK AK&6.8 0 Yes
357 SIG Pistol Y 40cal 40cal 2 No
358 Hoosier Rifle Y 308W AK&6.8 0 Yes
358/.25 WSSM Rifle N WSSM WSSM 0 Yes
40 S&W Pistol N 40cal 40cal 2 No
45 ACP Pistol N 45acp 45acp 2 No
450 Bushmaster Rifle Y 308W 223R 2 Yes
458 SOCOM Rifle Y 308W 223RM 2 Yes
50 BEOWULF Rifle N AK 223R-M 1 Yes
6.5 BR Rifle Y 308W AK&6.8 0 Yes
6.5 BRX Rifle N 308W AK&6.8 0 Yes
6.5 TCU Rifle Y 223R 223R 0 Yes
6.5/.25 WSSM Rifle N WSSM WSSM 0 Yes
6.5Grendel Rifle Y AK Grendel&AK 2 Yes
6.5LBC Rifle Y AK Grendel&AK 2 Yes
6.5x42 Rifle Y 223R 223R 0 Yes
6.8 SPC Rifle Y 68spc 68spc 2 Yes
6mm norma BR Rifle Y 308W AK&6.8 2 Yes
6mmAR Rifle N AK AK 0 Yes
6x45 Rifle Y 223R 223R 1 Yes
6x45(long) Rifle Y 223R 223R 0 Yes
7.62x39 Rifle Y AK AK 2 No
7.62x40 Rifle Y 223R 223R 1 No
7mmx40 Rifle Y 223R 223R 0 Yes
7mmx42 Rifle Y 68spc 68spc 0 Yes
9mm Luger Pistol Y 9mm 9mm 2 No
9x25 Pistol N 10mm 10mm 1 No
Tokarev Pistol N 9mm 38super 2 No

 

[kev74]

That's awesome! Thanks meketrefe!

 

[meketrefe]

NP @kev74. I didn't include all.
As you can imagine a number of them can be custom made with standard parts and the reamer for the caliber you want.
Read about some of them. There are some cool ones including a few even if you don't reload.
It all depends on what you are looking for. This year we are going to see if we harvest a couple of deer with the 35 gunner that has been a blast.

 

[kev74]

You gave me a lot to chew through. Thanks!

 

[Jem45472]

Your looking for same bolt, same mags, you reload, and gonna stay under 200 yards. Like it or hate it you're a perfect candidate for 300blk. I like 6.8,but went with 300 myself for the exact same circumstances you posted.

 

[Toecutter]

I have no expiriance with the round bit i've heard good things about the 25-45 sharps. Maybe others can chime in.

 

[Dantheman]

I have no expiriance with the round bit i've heard good things about the 25-45 sharps. Maybe others can chime in.

The Sharps company won't ship to anyone in NY. My buddy tried to buy an upper from them. They told him they wouldn't even ship to an FFL...just a gunsmith. They came right out and said they don't want to do business in NY.

So my buddy just ordered a 6.8 from Stag. Screw Sharps.

Dan

 

[Podmonkey]

i am going to assume you want more power. Best all around caliber is the 6.8 for a simple one. If you want more power than 223 yet use the 223 brass, the 6x45 or 6tcu are very good 6mm if you reload. 6x45 ammo can be found but not easy.
The 458 socom will give big holes in shotgun trajectories.
Or if you want 308 power from a ar15 build one 35 gunner.

I thought the ballistics of the big bore AR calibers, such as .458 SOCOM or .50 Beowulf, were more like that of a 45-70 load. Which is pretty cool I think. But more legs than a 12 gauge slug surely.

 

[Robin]

6.8 would get my vote. pretty much has it all, the ammo and reloading components are now being produced by all the major manufacturers making the price come down.
Robin

 

[meketrefe]

I thought the ballistics of the big bore AR calibers, such as .458 SOCOM or .50 Beowulf, were more like that of a 45-70 load. Which is pretty cool I think. But more legs than a 12 gauge slug surely.

It depends on what 458 bullets and what 12 slug, you also have ballistic tip sabots now with much better performance.
The evil is in the details.

 

[meketrefe]

I have no expiriance with the round bit i've heard good things about the 25-45 sharps. Maybe others can chime in.

IT is an easy and nice improvement over the 5.56. A nice white tail round. But the 6x45 or 6mm TCU do better due to the better ballistics and huge
assortment of 6mm bullets for everything.
For these I suggest a bit extra freebore and at least 20" barrel that is still very handy.
for example take the 6x45 with a 85gr speer hpbt with G1:.404 that with AA2230 can propelled at 2850fps from a 20" barrel for a nice hunting load.

No other round can do that from a 5.56 case (even the 25-45) simply necked up and can be loaded to full capacity in the original magazines
and with original bolts. There are other rounds that can be even superior loading with 90-100gr out to 2,3 coal from PRI, ASC or pmag magazines.

Barrels and dies are plentiful. I would just ask for a tad extra freebore or the 6mm TCU that is also simple.




I hope this helps.

 

[meketrefe]

6.8 would get my vote. pretty much has it all, the ammo and reloading components are now being produced by all the major manufacturers making the price come down.
Robin

6.8 in a 18" barrel can be pumped to propel a 95gr TTSX to 2,850 fps using xterminator.
So you do the math. Amazing round.

 

[Podmonkey]

It depends on what 458 bullets and what 12 slug, you also have ballistic tip sabots now with much better performance.
The evil is in the details.

I suppose sabot slugs come pretty close, but big bore rifles have greater range and precision still. Buffalo hunters used to take Bison at a thousand yards or more with the 45-70. Granted at that distance they were walking their fire into a massed herd at that range. What is the muzzle velocity of a stout sabot slug vs say a warm .458 SOCOM?

 

[meketrefe]

I suppose sabot slugs come pretty close, but big bore rifles have greater range and precision still. Buffalo hunters used to take Bison at a thousand yards or more with the 45-70. Granted at that distance they were walking their fire into a massed herd at that range. What is the muzzle velocity of a stout sabot slug vs say a warm .458 SOCOM?

Grain per grain not very different. 1,900fps for the 300gr socom, 1,650 for 3" hot 1oz slug or 2000fps for 300gr 12ga sabot.
The beowolf the same thing. Ballistics not very different than a powerful shotgun.
some rifled shotgun barrels can be very accurate like the savage bolt action.

Funny thing is shotguns with detachable magazines are so called AWs while those big bore are not but they are the same or even a tad more powerful for similar ranges / use.

so what is the definition of shotgun, the stamp in the brass?

 

[Cleck]

I got a chance to shoot one of these recently, it was awesome. Looked awesome, felt awesome, sounded awesome, didn't cost me a cent to build so that made it the most awesome. I say go for it

 

[capitalcrew]

6.8 was my choice.

Not to highjack.. but where did you find 6x45 commercially?

 

[meketrefe]

6.8 was my choice.

Not to highjack.. but where did you find 6x45 commercially?

Les baer sells uppers.
Midway sells barrels and dies so do others
Since it is a wildcat there is no much ammo. I saw blackhills and corbon produce some ammo at some
point but most likely ammo is custom order or the reload that is quite simple.

 

[meketrefe]

So I was thinking that since the 7mm-08 upper is now done I was thinking to retake the
35 Gunner project and add a few enhancements to it.

A) Very slight capacity increase
B) Very slight free bore increase in order to shoot faster 250gr and 280gr bullets and 310gr subsonic.
C) will need a 1:10 twist.

Perhaps this chamber should be the "35 BlackOps" version! lol. ... Even w/o the oppressor, the 310gr should be pretty quiet.

 

[Podmonkey]

Is that based on a .223 or 308 case?

 

[meketrefe]

Is that based on a .223 or 308 case?

That is based on the 7.62x39 or Grendel cases. Very easy to form and little trimming.

Here I put 3 x 35 gunner rounds next to other rounds and cats so you can get an idea...
The smeared stuff is sharpie from testing COAL in the chamber.

 

[SteyrAug]

Really hard to beat a 7.62x39 for all around use. Lotsa cheap ammo for plinking and good handloads will kill as well as a 30-30.

 

[Frankly]

I understand wanting 300 blackout for a suppressed weapon (moot point here). But given all the possibilities with 5.56 and 7.62 why would I want to split hairs with the hassles and expense of a less popular intermediate round? Isn't it getting a bit ridiculous? Why not just spend the money on refining the rounds and rifle that's readily accessible?

For the money that'd be spent the shooter could buy better ammo, an awesome scope, a better barrel....

And the OP did say, "same bolt, same mag" as 5.56 lol.

 

[SteyrAug]

If you have a fixed mag 300 BO, Gemtech makes a brake/can adapter that screws right on. Obviously you don't walk around with the can installed but..... it takes about 15 seconds to put it on or off.

7.62 ARs are not light and kick. The 7.62x39 upper goes on the AR 15. With the right loads it's fine for Deer or 2 leggers out to 200 yards. Gemtech also makes the brake/adapter for it and a 30 cal can is "snick, snick." (for those of us in free states)

As I have a 300 BO, I've never tried my 7.62x39 with subsonic loads but see no reason why they would not work.

 

[Jem45472]

I understand wanting 300 blackout for a suppressed weapon (moot point here). But given all the possibilities with 5.56 and 7.62 why would I want to split hairs with the hassles and expense of a less popular intermediate round? Isn't it getting a bit ridiculous? Why not just spend the money on refining the rounds and rifle that's readily accessible?

OP said he reloads, and stays under 200 yards. 300blk will move him to 30 cal on the cheap. Don't forget it's not just good for subs and suppressed, it excells in short barrels, that's why I chose it for an 8" pistol build. Granted if I was doing another 16" I may be tempted to go 7.62 for plinking, or 6.8 for hunting.

 

[Eddie Gunks]

OP said .

OP said same bolt, same mag.......