[GrtWhytHype]

Just about to finish my first build which was an entry level knock around 16 inch 5.56. I'm just waiting for the barrel to come in. Because of the uber wait times on everything I've decided to get started early on my next build. Gonna go the SBR route an was interested in playing with a fun caliber. Seeing as how a SBR would be mainly for CQC, what's a nice big caliber that would perform well in CQC situations but still be useable in an AR build? Any suggestions welcome.

 

[silverado113]

.300 blackout.

 

[AgentTikki]

.300 blackout
.458 socom
.50 beowulf
6.8 spc ii


My fav is the 300 blackout

 

[locutus]

5.56X45.

There are many good reasons why the military uses it.

 

[bonney]

with a 12" or so barrel, and a 7" or so sound suppressor, using the deep penetrating Nosler Partition softpoints, the 223 does fine, and it retains the ability to use GI ammo, reach 1/4 mile, and use the .22lr conversion unit. the other calibers give up these major advantages, for no real offsetting reason to prefer them.

 

[Quentin]

5.56X45.

There are many good reasons why the military uses it.

I agree 100%. When deviating from 5.56 you really have to be able to justify the change. Many good larger calibers have been mentioned here but how do they work any better than 5.56 for clearing a room? Maybe you have reasons but I don't see them myself.

No doubt there are lots of good applications of those calibers but for CQC?

 

[2tone0311]

I agree 100%. When deviating from 5.56 you really have to be able to justify the change. Many good larger calibers have been mentioned here but how do they work any better than 5.56 for clearing a room? Maybe you have reasons but I don't see them myself.

No doubt there are lots of good applications of those calibers but for CQC?

Agreed. 5.56 does it's best under 200 meters terminally (in side tissue) round fragments real well plus 2 shot under one second on target will shock the central nervious system therefore incapacitating your target. Head shots work well too

 

[KingTiger]

8" or 9" 300 BLK.

You won't go deaf & be temporary blinded if you have to use it inside without a suppressor. It uses standard AR mags with no loss of capacity. I also like the 7.62 sized holes it makes vs 5.56.

 

[Sniper03]

We did a little testing with the 300 Blackout in Texas in November. Shot regular loads and even loaded some special rounds and use a suppressor on it. To say the least it was very impressive and fairly quiet! We also shot some coyotes with it which worked out well. It was basically designed to be used on SBR Platforms with Suppressors. Just as a note it also seemed quieter in our testing to even run the 308 Suppressor on the 5.56 rifles.

03

 

[AgentTikki]

Just as a note it also seemed quieter in our testing to even run the 308 Suppressor on the 5.56 rifles.

03

Hey Sniper, can you expand on this, I'm not sure what you mean.

 

[PittTactical556]

.300 blackout

 

[orangello]

Dare to be different; go 10mm.

 

[GrtWhytHype]

Already did the 10mm. Just ordered the new RIA 10mm from CTD.com. Waiting for my ffl to get it.

 

[JonM]

Hey Sniper, can you expand on this, I'm not sure what you mean.

30 cal cans work better than 556 cans on 556 guns. mainly due to the larger space inside a 30cal can more available volume means a quieter shot.

to the OP: 9mm and 45acp along with 460 rowland make superb cqb rounds. pistol ammo out of a rifle is a different animal than out of a pistol.

 

[combateffective4]

Just about to finish my first build which was an entry level knock around 16 inch 5.56. I'm just waiting for the barrel to come in. Because of the uber wait times on everything I've decided to get started early on my next build. Gonna go the SBR route an was interested in playing with a fun caliber. Seeing as how a SBR would be mainly for CQC, what's a nice big caliber that would perform well in CQC situations but still be useable in an AR build? Any suggestions welcome.

bite the bullet but a sbr Kriss vector super v I know you'll be capable with that sob

 

[orangello]

Already did the 10mm. Just ordered the new RIA 10mm from CTD.com. Waiting for my ffl to get it.

Do it in an AR platform & i will be impressed and jealous. That extra barrel length might buy some impressive fps. With such a reloader's cartridge, a longer barrel might give you options on the powder choice (not a reloader here, just guessing).

 

[oldpapps]

"get started early on my next build. Gonna go the SBR route an was interested in playing with a fun caliber. Seeing as how a SBR would be mainly for CQC, what's a nice big caliber that would perform well in CQC situations but still be useable in an AR build"

The 300 AAC Blackout shines with short/er barrels. And is a fun round.
SBR more or less precludes the 6point8 and 6.5 G.
Maybe one of the whopping big .458 and larger rounds.
Many options. The budget for this project could be a factor.

 

[sweeper22]

I'm kinda toying with the 300blk idea myself right now. It really all boils down to your budget and how you want to use the rifle. I'll probably buy a 16" 300blk Daniel Defense V7, and then hopefully add a SBR upper and suppressor in the following months...but that's $400 worth of paperwork and potentially several months wait parlayed with the actual cost of the hard goods.

300blk is not going to rival 308 or even 5.56. It sort of falls somewhere between a pistol carbine and an actual "high powered" rifle round. What is does offer, is versatility. The supersonic rounds offer similar ballstics to a 7.62x39 (AK), while the subsonic (through a SBR) seem to mimic 9mm. While considerably heavier than 9mm, you'll have a smaller diameter, lesser velocity, and similar energy.

Or maybe I'll just buy an M1A.

 

[JonM]

Once you sbr a lower with the tax stamp and engraving you can get as many uppers or barrels as you care to. The stamp is just for the lower.