30 HRT

[rsilvers]

A carbon length gas system on a 16-inch the 300 BLK/Whisper is only useful for guns that are set up to shoot primarily supersonic loads.

That used to be true, but 300 BLK solved that about 1.5 years go.

The AAC 16 inch barrel is carbine. It shoots subsonic and will lock open on an empty mag. If you put it on a full auto lower, it will cycle at Colt M4 cyclic rates.

Agreed adjustible gas is not needed. I am not even aware of any such system being sold - for a good reason.

[320pf]

That used to be true, but 300 BLK solved that about 1.5 years go.

The AAC 16 inch barrel is carbine. It shoots subsonic and will lock open on an empty mag. If you put it on a full auto lower, it will cycle at Colt M4 cyclic rates.

Agreed adjustible gas is not needed. I am not even aware of any such system being sold - for a good reason.

AAC did the 300-221 Fireball based Wildcats a great service by getting the cartridge standardized be SAAMI. In addition, the AAC group has also encouraged the development of several bullets optimized for the 300 BLK (like the Sierra 125 gn MK and the Barnes 110 gn TTSX) and we have all benefited from this. However, AAC did not do any real heavy lifting in the ballistic development of the 300 BLK, it was all done by the 300-221 Fireball Wildcat community and by J.D. Jones.

This problem was solved more than 1.5 years ago and it was NOT my the AAC engineers. It was solved 10-to-15 years ago by the shooters that built and shot the 300-221 Fireball based Wildcats. We found two solutions to shooting subtonics with a carbine length gas system.

The best solution is to go with a pistol length gas system. As I stated in my post, A properly set up 16 inch barrel with a pistol length gas system will shoot subsonic loads with bullets AS LIGHT AS 150 as well as bullets to 240 gn. In addition, the subsonic loads and will lock open on an empty mag, even with the light 150 gn bullets as well. This solution also gives the shooter access to more powder choices (like 2400, W296, H110, A#9, Lil'Gun, 4227, A1680, and 4198) for use with the light weight subsonic bullets.

The AAC engineers chose the second solution and that is to restrict the loadings to two or three powders. In general, RE-7 is too slow and only appropriate for use with the heavier bullets (>/= ~200 gn). By your own admission. See your quote below.

The solution to that problem - and I agree it was a problem historically - was to use powder that is more compatible with ARs. A1680, RE-7, and H4198 are some examples.

Now you might ask why would anybody want to shoot light 150-168 gn bullets subsonically? Just think knock-down steel. What would you rather shoot 200-240 gn bullets at 1050-1100 fps or 150-168/180 gn bullets at 1050-1100 fps. Which load do you think would offer faster recovery and transition/acquisition of the next target?

In closing, as an AAC representative, you should only take credit for what AAC has done, which is pretty substantial, and acknowledge the ingenuity of the wildcatters that did most of the development for this cartridge. By claiming such things like:

"That used to be true, but 300 BLK solved that about 1.5 years go….

Only serves to detract from AAC's reputation.

[rsilvers]

320pf - yes, those powders existed before 300 BLK and some hand loaders used them, but there was absolutely no ammunition being sold which would cycle without pistol-gas. So by solve, meant we sold ammunition and made guns. Once we did that, other companies could also make compatible guns. Noveske, Daniel Defense, etc.

By the way, I am not saying carbine gas is better. 16 inch barrels can be made to work well either way.

[rsilvers]

Which load do you think would offer faster recovery and transition/acquisition of the next target?

It would never occur to me to seek out less recoil than the very mild subsonic 220 recoil. If price is an issue, there are cast bullets in 200+ grain.

[rsilvers]

The best solution is to go with a pistol length gas system. As I stated in my post, A properly set up 16 inch barrel with a pistol length gas system will shoot subsonic loads with bullets AS LIGHT AS 150 as well as bullets to 240 gn.

Only if you make the gas port too large for supersonic ammo and larger than needed for virtually all factory 300 BLK subsonic ammo to work even unsuppressed, or require an adjustable gas block. If either of those things are ok with you, and they do seem ok with you, then sure.

[AR15barrels]

I think that I just realized who 320pf is and that he still has the first 300x221 barrel I ever chambered.
I'd like that barrel back if you and Bruce are done tinkering with it now...

[320pf]

Hi Randall,

I am travelling for the next 10 days. I all mail you your barrel when I get back. Is the mail contact info on your web page still good?

I brought the barrel with me to the SMM3gun match in March, hoping to see you there. But it looks like you did not shoot the match.

[AR15barrels]

Is the mail contact info on your web page still good?

Yes.
No big rush, it's just the first barrel I ever made...

[constructor]

320pf - yes, those powders existed before 300 BLK and some hand loaders used them, but there was absolutely no ammunition being sold which would cycle without pistol-gas. So by solve, meant we sold ammunition and made guns. Once we did that, other companies could also make compatible guns. Noveske, Daniel Defense, etc.

By the way, I am not saying carbine gas is better. 16 inch barrels can be made to work well either way.

No ammunition was being sold but 4198 can be reloaded and work in a carbine length gas system that is ported to work with supersonic and subsonic loads.

[Maryland_Shooter]

300 BLK and 223 proof loads are 72,000 psi. The fact that you have one with a blown primer just means that it was shot in a rifle that failed the proof test due to a tight chamber, bore, or short headspace.

Wonder what primers a proof load uses?