No such thing as over gassing with direct impingement as the carrier moves away from the tube venting the gas anyway. You should have an adjustable gas block and pistol length or shorter gas...
Liked On: 09-01-2016, 11:18 AM
Have a look at this link. Just breezed through it but it could be of help before you get the Black & Decker out. 300 BLK Port Size Testing (http://micromoa.com/300-blk-port-size-testing/)
Liked On: 09-01-2016, 11:17 AM