300 Blackout vs .308 Win: Which Round Reigns Supreme in AR-15s?

[TEXASforLIFE]

I was just reading some stuff online and carbine length gas system barrels can be found and typically work fine for .300blk but can have issues under 16in. The 16in barrels I've used are all pistol length gas systems. These 16in barrels are Wilson, BA, and Faxon and maybe one or two more different brands.

BARREL, 300 BLACKOUT, RECON, 16", FLUTED, STAINLESS, GLASS BEAD, 1-7

Wilson Combat has been the innovator in custom pistols, long guns, and accessories since 1977. Home of the Wilson Combat 1911, EDC X9, WCP320, and more!

wilsoncombat.com

i'll check when i get home on the 16" gas length. lots of the 450bush and big bore ar15 cartridges will limit gas length use, so there might be something to that

 

[TEXASforLIFE]

i've been building ar's for nearly 12 years (just over 10) and i've come across many brands that have their own idea on gas port sizes with specific gas lengths. some have been undersized and some the opposite. when the 6.5creed ar hit the market it didn't hit well.............well maybe some factory builds did, but for those who roll their own it became a pita! aero precision is the only brand i've used that had the rifle length gas that could run with standard weight buffers and a non-adjustable gas block. i have several other brands with standard and +2 gas that required more than an adjustable gas block to run correctly.

 

[UC_Guy 1971]

When I lived in color-ado I found out that you cannot hunt big game with a 5.56. I picked up an AR-10 in .308. Still have it, don't shoot it much, but I consider it my hunting rifle.

At some point my son-in-law decided that he wanted to dip into the. 300 BLK world. I couldn't do it. I did do something ...similar?

I went with 7.62x39. I built an AR-47/AK-15. It takes the C-Products Duramags; you can use a traditional AR lowered with these.

So to make a short story really long, I would say .308 reigns supreme in the AR platform. For me.

 

[Talyn]

i've been building ar's for nearly 12 years (just over 10) and i've come across many brands that have their own idea on gas port sizes with specific gas lengths. some have been undersized and some the opposite. when the 6.5creed ar hit the market it didn't hit well.............well maybe some factory builds did, but for those who roll their own it became a pita! aero precision is the only brand i've used that had the rifle length gas that could run with standard weight buffers and a non-adjustable gas block. i have several other brands with standard and +2 gas that required more than an adjustable gas block to run correctly.

My PSA PA-10 Gen 3 (rifle-length/Adj GB/DI) in 6.5CM runs fine.

But will supplant it in the herd when PWS releases its' Mk.2 MOD 2 (piston) in 6.5CM later this year.

 

[Kir]

Didn't read all the posts, but wasn't the AR-10 made in .308? Don't know anything about the Blackout caliber.

 

[TEXASforLIFE]

Didn't read all the posts, but wasn't the AR-10 made in .308? Don't know anything about the Blackout caliber.

Back in the 50's with armalite/Eugene stoner iirc. Not 100% about that, but it was the 1st short action cartridge in that platform

 

[TEXASforLIFE]

I was just reading some stuff online and carbine length gas system barrels can be found and typically work fine for .300blk but can have issues under 16in. The 16in barrels I've used are all pistol length gas systems. These 16in barrels are Wilson, BA, and Faxon and maybe one or two more different brands.

BARREL, 300 BLACKOUT, RECON, 16", FLUTED, STAINLESS, GLASS BEAD, 1-7

Wilson Combat has been the innovator in custom pistols, long guns, and accessories since 1977. Home of the Wilson Combat 1911, EDC X9, WCP320, and more!

wilsoncombat.com

iirc this is the barrel i have and did confirm it has the carbine length gas. it's this exact barrel below

BC-15 | .300 Blackout | 16" 416R SS Black Nitride Black Wolf Fluted Heavy Barrel | 1:8 Twist | Carbine Length Gas System

16" .300 Blackout Barrel with a 416R Stainless Steel finish, a Heavy Black Wolf Fluted Barrel profile, Carbine Length Gas System, and a 1:8 Twist

www.bearcreekarsenal.com

 

[TEXASforLIFE]

i bought it only to verify velocities against the two 8.5" aero precision barrels i have.

 

[TEXASforLIFE]

My PSA PA-10 Gen 3 (rifle-length/Adj GB/DI) in 6.5CM runs fine.

But will supplant it in the herd when PWS releases its' Mk.2 MOD 2 (piston) in 6.5CM later this year.

did you buy the complete upper or a complete firearm from psa? what buffer weight are you using

 

[Talyn]

did you buy the complete upper or a complete firearm from psa? what buffer weight are you using

I got the complete upper from PSA but built-up a stripped PA-10 lower to my standard fit of parts.

I always use a Spikes T2 buffer in both AR15 & AR-10 builds.

 

[Shibadog]

Dude it's the SAME caliber, just different cartridges. Don't sound like a liberal

Don’t think so. Same bore size but big difference in performance. A .300 Win Mag is also the same bore, as is .30 carbine. .300 BO is a short range fairly low performing .30. .308 is long range, much more powerful round.

 

[TEXASforLIFE]

Don’t think so. Same bore size but big difference in performance. A .300 Win Mag is also the same bore, as is .30 carbine. .300 BO is a short range fairly low performing .30. .308 is long range, much more powerful round.

they ARE the same caliber ie .308/30cal as i stated in your reply. cartridge wise i agree about a big difference

 

[Belt Fed]

they ARE the same caliber ie .308/30cal as i stated in your reply. cartridge wise i agree about a big difference

You'd have to be a LIBERAL not to know that.