Which way do I go George? (IE, Which caliber to build my next AR-15 in?)

[The_Hammer_Man]

Hi guys,

I'm trying to decide which caliber to build my next AR-15 upper in?

Some background...

I'm going to stick with carbine (14.5"-16") heavy barrel or I might go up to an 18 incher and build a "SPR".

As far as price of ammo is concerned it's not really an issue but the choices seem to be
Ammo in cheapest to most expensive

5.45x39 the only ammo cheaper than this stuff are .22 lr's.

7.62x39 second cheapest and easiest to get ammo in the world (IMHO)

5.7x28 weird little round, not too expensive to shoot, readily available.

6.8 SPC for this round I'd probably go with an 18" barrel.. I've heard they don't perform all that well in carbine length barrels. Ammo is pricey too!

.450 Bushmaster: expensive ammo but available

.458 SOCOM: again expensive/available

.50 Beowolf : same as above


I'd really like some input from you guys!

Thanks,

THM

 

[jcox265]

what ar style do you have now?

 

[AcceptableUserName]

i think the .50 beowulf would be fun. you already have some 5.56 presumably, so might as well have some fun with it right?


after that, I'd go 5.45

 

[Ranb]

I own and shoot mine in 5.56, 458 socom and 300 whisper. I have also shot them in 45 acp, 22lr, 9mm and 7.62x39.

The pistol calibers are cheapest if you do not reload. 300 whisper and 458 socom are not very expensive if you reload.

If you are going to hunt, then use 7.62x39, 6.8, 458 socom, 450 bushmaster or 300 whisper depending on the game. The Speer 70 grain bullets can be used on game up to small deer in the 5.56.

Ranb

 

[Shadow Man]

6.8 SPC for this round I'd probably go with an 18" barrel.. I've heard they don't perform all that well in carbine length barrels. Ammo is pricey too!

If you go the 6.8SPC route, get a chamber that can fire the GenII stuff. I believe it's called 6.8SPCII, but I could be wrong. Appears they re-worked the cartridge/loading and can now achieve the same velocity out of an 8in barrel that they achieved out of a 16in a couple years ago. You'd have to do some independant testing, but it looks good. You're right though, it is bloody expensive unless you reload.

 

[MatthewVanitas]

Assuming you have a .223, the other small-calibres would seem pretty redundant. You'd just be stocking yet another cartridge that would perform close to or inferior to .223 and "feel" practically the same when shooting.

If you can get a suppressor in your state (or have one already) and are willing to do so, I'd say .300 Whisper, and get one of those gas-tubes where you can turn it off from the outside and make the rifle straight-pull on demand.

If you want the biggest contrast, and/or short range hunting and aren't too big on suppression, any of the rifle .45s sound cool, or even .50.

You can suppress the bigger cartridges, but it's harder and even with subsonic rounds they're not really hearing safe, according to this:

Can I shoot subsonic loads? (in .458 SOCOM)

Considering this was part of the original design intent, the answer is a resounding YES. Both the 500- and 600-grain subsonic load has proven quite popular and will function without issue through the uppers.

How loud are the subsonic loads?

While not as loud as the 300-gr high velocity load, they are still not quiet enough to forego ear protection.

What about putting a suppressor on one of these?

Several uppers have been fitted with suppressors, either muzzle mounted or semi-integral versions. Different brands have been reported, such as SRT and GemTech, as well as Form 1 versions built by qualified individuals. With the 500- and 600-grain subsonic load they tend to make for a very nice and relatively quiet package. Suppressing a low pressure large bore cartridge has its challenges, and Hollywood has created a false impression of how quiet a suppressed rifle typically will be. These uppers are not like you see in the movies and a lot of the noise is from the action cycling. If you want the ultimate in suppressed .458 SOCOM, the Remington 700 Etronix version with semi-integral suppressor would have to be it. Other calibers are far more suited to suppressing but the SOCOM is no slouch. Remember that the 11.63 x 33 was used in suppressed bolt guns in Vietnam ….

http://www.teppojutsu.com/458FAQ.htm#_Can_I_shoot_subsonic_loads

 

[The_Hammer_Man]

I have several 5.56 NATO chambered rifles.

2x Bushmaster M17s bullpup one modified and one in factory condition.
(good shooters and great brush and cqbesque rifles.. a bit heavy but fun)

2x 16" AR-15s one DI and one with the Adams Arms piston drive on it.

1x 20" built on a Spikes Tactical receiver set.
This one is my varmint gun. very reliable and accurate as you could want

1x DPMS SASS in 7.62 NATO ...
Need to get reloading for this round.. cuz it's a pricey beast to feed!

1x Tactical Solution M422 upper.. this is my cheapest to shoot rifle and one of the most fun.

1x Alexander Arms .50 Beowolf Flat-Top w/ Railed Forearm and their muzzle brake.
This is THE most expensive to own/fire caliber I own. Even reloading it is expensive .

Along the way I've owned or fired alot of different rifles but I keep coming back to the Remington 700 for bolt guns and the AR-15 for semi-auto.

Since I retired I've gotten more into precision shooting and have had good luck with my AR builds to date. Now I'm looking into trying a completely different caliber but want to stay economical if possible.

 

[cz85cmbt]

What are you looking for out of this new AR build, precision or economics. The 5.45 is economical but if you reload .223 it's kind of redundant and it sounds like you already reload so it'd be far more economical to buy a dies than a whole new rifle. The 6.8 isn't a bad choice but bullets have mediocre external ballistics I look at the 6.8 as a refined 7.62x39 which in AR 15's seem to have feed issues with high cap magazines. In a 19.5" barrel the 6.5 grendel would be a great light recoiling long range rifle, in a 16" barrel you'll lose maybe 150fps with light 90gr but only about 100 or less with 120-140's.

 

[GunsBeerFreedom]

The 5.45. And learn to reload it. If you do good, history will remember you kindly.