Mated an Anderson ar-15 lower to gen 4 9mm upper with feed issues. Current configuration is 7.8 oz buffer, 308 spring, stern defense conversion with Glock mag. Firing 115 FED brass.
Also tried to use same set up with Endomag PMAG inserts, carbine spring, and 5.4 oz buffer and different combinations.
I’m assuming my inconsistent feed issues are related to the round placement in the mag and how it contacts the bolt face. The endomag set up was smashing the rounds into the top of barrel face but only seemed to do it intermittently on fully loaded mags on the first 15ish rounds. The stern defense Glock conversion cut the FTF issue in half but because the round has less distance to travel it is driving into the bottom of barrel face.
I’ve invested more money in the mag and buffer set up than the entire gun and getting frustrated. I’m trying to avoid modifying the barrel face with any kind of “ramp” but I don’t have any more ideas.
The heavy buffer set up I feel is the correct direction but I’m smashing the projectiles into the casings and altering the pressures on some of the chambered rounds. I can hear the difference when fired sometimes if they don’t fail to feed.
I might purchase a Taccom feed ramp but not sure if that’s an option with an ar-15 lower yet.
Any advice would be appreciative.
Thanks
-Russ