PLA+ no supports 100% infill. will use a m4x25mm bolt might have to file bolt head diameter down to fit you upper tight. You can get way with a m4x20mm bolt too. JB Weld Recommended Designed by Justmejohn44 follow on thingiverse
LBRY Tags: guns; mac 9; mac 11; 3d printing
UMP 11/9 Handguard and Charging Handle Remix
Latte Bar (Mac11 Glock Bar Mag Release)
UMP 11/9 G36 Sloppy Seconds binary safety v1