Best caliber for suppressed SBR

[Shmackey]

Hey kids. Long time.

Looking into a suppressed SBR. Either AR-15 or AR-10 platform. I already load 5.56 and 7.62 and have mags for pretty much any typical semiauto rifle.

Been looking at .300 blk but not totally blown away by ballistics. Also .458 SOCOM and the usual big thumpers. I've made subsonic .308 before but don't see any advantages there. (Are there any necked-up thumpers based on that parent round?)

Anyway, what's the consensus on caliber for a suppressed SBR? Extra points for using stock mags, or at least factory mags that really run every time.

 

[Yarddog]

300 blk would be a good choice IMO ; )
Y/D

 

[Robert]

5.56 or 300. 300 may not be a long range cartridge but that not what it was designed for. It was designed to be subsonic and hard hitting out of an SBR with a can.

 

[Havok7416]

.300 Blackout for a can. Stock mags and great sound signature.

 

[gotboostvr]

There's 357 AR Rimless. It's a 223 necked up past 30 cal to a straight walled 357 caliber.

Same bolt and mags as 223/300blk.

The 45 to 50 caliber bullets will bring more thump, but less capacity.

You could build a AR10 in 338 federal, 358 Winchester etc all are based on 308 brass. So same bolt/mags

When you ask for the "best" Suppressed SBR caliber do you mean longest point blank range, most energy. All are going to be limited to the same speed so it's which caliber is the heaviest most aerodynamic bullet available.

Which is probably 30 cal. Which means 300blk is probably the "best"

 

[DukeConnor]

Us kids like 300 bo for supressors.

 

[adcoch1]

45 raptor, and the 308 based 375 cal. Sorry can't remember what its called. Also I've heard of 44x1.8", just a chopped down 308 case with a 44 mag bullet in it. Uses shortened 444 marlin dies to load. In the ar 15 platform the 458 SOCOM, 450 bushmaster, and the 50 Beowulf are all readily available. I love the idea of the 357 maximum rimless too, basically a straight walled 223 with a 357 bullet as mentioned earlier.

 

[jmorris]

Best for what?

.22 lr is a natural, cans are cheap as is ammunition. 9mm is pretty cheap and a 147 grain sub sonic bullet from one doesn’t give up much vs a 150 grain sub from a 308 or 300 blk. If you want energy, once you set a speed limit (speed of sound) mass is the only thing that can give you that. The 458 socom with 405+ gn bullets is the best preforming subsonic rounds I have used on hogs that were not caught on a trap.

As far as sound is concerned small charges of fast powder are better than larger charges of slower powders.

Again, that makes a .22lr a winner.

They even make a “moderated” air rifle seem loud in a side by side comparison.

 

[mcb]

300 Blackout is probably the most economical choice for both building and feeding. Very few specialized parts to build a 300 BO and there is lots of commercial ammo on the market for 300BO both super sonic and sub sonic and lots of reloading components.

458 SOCOM or 50 Beowulf are probably your best choices for maximizing your energy while still remaining sub sonic and reasonably priced.

450 Bushmaster can perform very similar to 458 SOCOM if you willing to resize heavy .458 bullet down to .452.

 

[someguy2800]

I would put serious consideration on a 9mm or a 45 ACP. My 9mm pistol is a hoot, cheap to feed, and very accurate out to 100 yards. Its waiting for its suppressor to get out of jail. 9mm out of my 10" barrel only requires a couple inches of hold over so unless your looking to lob really long range the subsonic rifle cartridges don't give you much and are about 10 times the cost to feed.

 

[CraigC]

For what purpose? I don't see how we can have this conversation at all without knowing this.

450 Bushmaster can perform very similar to 458 SOCOM if you willing to resize heavy .458 bullet down to .452.

Absolutely no need to resize .458's for use in the .450BM. Already a huge selection of bullets 250-400gr and no use whatsoever to go heavier than that.

 

[FL-NC]

223 if you want cheaper ammo supersonic (it will crack), 300 B/O if you don't mind the expense of pricier ammo or reloading your own subs. It will be quieter.

 

[MistWolf]

Hey kids. Long time.

Looking into a suppressed SBR. Either AR-15 or AR-10 platform. I already load 5.56 and 7.62 and have mags for pretty much any typical semiauto rifle.

Been looking at .300 blk but not totally blown away by ballistics. Also .458 SOCOM and the usual big thumpers. I've made subsonic .308 before but don't see any advantages there. (Are there any necked-up thumpers based on that parent round?)

Anyway, what's the consensus on caliber for a suppressed SBR? Extra points for using stock mags, or at least factory mags that really run every time.

Your question makes sense only if the only use for the fiream is to shoot suppressed. If that's the case, just get a .22 rimfire, install a suppressor and shoot subsonics.

However, I suspect you have another purpose in mind. In that case, simply get a firearm in the caliber that will do the job and suppress it.