.300 AAC Blackout/Whisper Results Here

[bowfin]

Some controversy over whether others have had better results than Savage did while trying to use this cartridge at subsonic levels.

Could it be that cast boolits might be a better choice for subsonic loads than jacketed? How about twist, barrel length, rifle platform, with or without a silencer, whatever I can't think of adding.

I have no dog in this fight, and reports from the field trump everything else. Here is where the forum can pool their knowledge and figure out what works and what doesn't to the benefit of the entire shooting fraternity.

Let's keep the :takinWiz: to a minimum and try to figure out from where comes success or failure with this cartridge/rifle combination.

[Tank56]

I don't know exactly what Savage was using as their parameters, but using the Lee 200 grain gas check design (with out gc) has worked well for me in a 1in 10 , 20 inch internally suppressed bolt rifle and a 16 inch, 1 in 8 twist AR.
I have not used any of the heavy weights (220 or above).
A few things to know, first I had no problem getting good accuracy with mid range bullet weights(140 to170) at supersonic velocities. This goes for cast or jax. Same for functioning in the AR gas system. Feeding from the mag in the AR system was a devil of a thing until I read about the simple trick of taking a dremil sanding drum to the ridge in front of the magazines. Sand it down to a 1/3 circle between the walls of the mag and it should work with both the .300/.221 or the .223 as needed.
I've had no problems with the Remington factory ammo in either rifle.
Any problems Savage had with bullet stability/subsonic performance should have been overcome by barrel twist, but it may not be that simple. One of the most fascinating things I witnessed was 200 grain bullets going end over end tward the target on a sunny day. This
was from the 16 inch 1 in 8 barrel. I still had a little accuracy from the 1 in 10 barrel, possibly due to longer barrel and suppression getting just a little more velocity. I don't always have use of a cronograph so I can't say for certain.
Someone else should speak to the effectiveness of sub-sonic cast boolits on game, as my experience is limited, but it seems like the bullets used in factory loads are meant to tumble. I'd think a soft lead boolit would tumble, bend and do all manner of damage to a critter on the way through. This is conjecture though.

[L1A1Rocker]

Could it be that cast boolits might be a better choice for subsonic loads than jacketed? How about twist, barrel length, rifle platform, with or without a silencer, whatever I can't think of adding.



There's a lot of good info in the original NOE 247 Whisper/BLK group buy thread.

[Idaho Sharpshooter]

I fiddled around for three weeks, getting an accurate subsonic load for my 300 BLK AR-pistol with the 247 bullet and a YHM Cobra II 9mm Suppressor. 2moa at 100yds. I ended up going 1.3gr higher to make up for the 90fps loss thru the can.

Rich