300blk Sbr Acr conversion

[bigdog2003_99]

I just finished my 300blk build on my Acr last week. It runs 125 gr supersonics and 220 gr subsonics so far. It wouldn't cycle the 178gr subsonic reloads though. Now I just need to find powder so I can make more ammo to test.

Pics






Short video of the testing with a very limited supply of ammo for now.
https://www.youtube.com/watch?v=5-Mk6qHAAg4

[dellet]

Looks like fun!

Not sure how close you are, will help with the subs.

viewtopic.php?f=179&t=85869

[bigdog2003_99]

Good looking out man! He's somewhat close to me, hopefully I can get a couple of pounds to start off.

[Bugspray]

Sweet rifle! Nice work!

[bigdog2003_99]

Thanks dude

I snagged some powder last week but still can't get any 1680.

I'm loading up some 208gr amax's with some h110 and Lil Gun. It will cycle and lock the hammer back but won't pick the next round up.

My general load workup right now is
1.358 casing length
208gr amax
2.13 OAL
8.5 gr of Lil gun
Winchester Primer
slight crimp

I'm not wanting to open the gas port more but might need it. It's currently at .085 and works with all factory ammo I've came across. Just not subsonic handloads.

ETA, I tried this with 10.6 gr 1680 instead of Lil gun and it still didn't cycle so I bumped the port up slowly and now it cycles but won't lock back. I'll be doing more testing this week sometime.