300 Blackout ammo for 1-7 bbl subsonic

[Trauma147]

Hi everyone! I recently bought an AAC 16" 1-7 twist upper chambered in 300 Blackout for my AR. I got in on the Templar Tactical group buy and bought an Ark30 suppressor and want to shoot subsonic ammo. (Obviously. ) In my research, I read that the 1-7 will stabilize the 240gr and heavier bullets better than the 1-8 and that's why AAC went to the 1-7. I haven't found any factory ammo heavier than 240gr. I reload, and saw that Midway had primed Remington brass for about .25 each for 2000. In looking for factory ammo I saw a lot of lighter stuff (110-150gr) and was wondering what will shoot best supersonic w/o suppressor and subsonic with suppressor. Also, any reload data would be appreciated. Bullet brand, weight, powder, primer and cases. Thanks!

 

[rbdub474]

Re: 300 Blackout ammo for 1-7 bbl subsonic

I have had good luck with 208gr. AMAX and 220gr. SMKs with my 1-7 Noveske barrel. I think some are also using the 247gr. cast lead offerings.

I only use the lighter 115-125gr. stuff for supersonic loads.

 

[leadbullet]

Re: 300 Blackout ammo for 1-7 bbl subsonic

you don't need a 240 gr to go subsonic, the 220 SMK are doing a really good job with 11.2 gr of AA 1680.
hope this helps.

 

[country888]

Re: 300 Blackout ammo for 1-7 bbl subsonic

200 gainrs and up work just fine for subs. I use the 208 gn amax for subs. You asked about a supersonic load also. I really like the 110 gn vmax with H110. I have also used 125 gn ballistic tip with great accuracy. I convert 223 brass for my blackout and use cci small rifle primers.

 

[jkkfam89]

Re: 300 Blackout ammo for 1-7 bbl subsonic

has anyone else had issues with the subsonic rounds? When I fire the first round, the rifle does not load another and the gun jams... Everytime. Only with subsonic though

 

[finbox]

Re: 300 Blackout ammo for 1-7 bbl subsonic

I run 175 SMK's at 1000fps the key is having a adjustable gas block.
With 11.2 aa1680.

If you don't have a adjustable gas block try a lighter buffer then try to drill out the gas port.

 

[country888]

Re: 300 Blackout ammo for 1-7 bbl subsonic

Bully, what barrel are you shooting? Is it the first round only that it jams on or all of them? What bullet are you shooting? Give us some more info.

Sounds like its short stroking. Not enuff gas.

 

[The King]

Re: 300 Blackout ammo for 1-7 bbl subsonic

many 300BLK's short stroke without the can on.

I shoot 225 hornady's using the load specced for 220's from AAC.