Be careful with the Sub-x 190's, I could not get them to feed reliably without bullet setback using several barrels. I don't know if it's a feed ramp issue or what but it's not a problem with the Sig. If you look at the barrel extension on the Sig, it's a lot longer than a typical AR15/300 blackout extension. My upper receivers were M4-type, VSeven.
I have no issues running any subsonic projectile on my 8" (other than the Hornady 190 Sub-X) but I hand load and use two specific powders which will cycle anything. I also use lightweight titanium BCG's and captured lightweight buffer systems which helps.
I have no issues running any subsonic projectile on my 8" (other than the Hornady 190 Sub-X) but I hand load and use two specific powders which will cycle anything. I also use lightweight titanium BCG's and captured lightweight buffer systems which helps.
