I've put together a rifle for my nephew from a bunch of extra parts, one being a 26" WOA match rifle barrel. I cut the barrel to 20" to make it a bit handier but have kept the original rifle +2" gas system. Got to the range and while it shoots very accurately it seems to be undergassed. Using crappy Wolf steel case ammo to sight the scope, it would either leave the spent case in the chamber, or eject and not load a new round. So it is short stroking, probably because it's missing six inches of barrel in front of the port. I didn't expect this to be a problem, but here it is. It would lock the bolt back with a couple 80gr Amax loads I had on hand but these are single feed. PMC ball with a different mag seemed to work a little better but I think is on the edge. Definitely not a vigorous ejection cycle. I want him to be able to shoot inexpensive ball ammo (not necessarily steel case junk) in it so I need to make it function better with it. New barrel or shorter gas system are out for now, I need to deliver it in three weeks. He'll be hunting coyotes and plinking with it.
So far some options I've come up with are to open the gas port a little (how much?), Wolf reduced weight buffer spring, lighten the recoil buffer (currently rifle A2 style), remove some weight from the M16 style bolt carrier, anything else I'm missing? I really don't know how much weight to remove from the reciprocating assembly to make the improvement so am looking for guidance/experience there. Reversible modifications preferred but I'm looking at everything right now. Appreciate any insights.
