Magazine loader/unloader I designed for use specifically with 300BLK and a P-Mag but should work for all 5.56 Mags.

Prints in 3 pieces. Body, Lever, Pivot.

Body only needs a small amount of support for the gap caused by the mag release latch.

Lever needs support for one of the lobs.

Pivot can be printed on it's flat face. 

There is a spot for a m3x8mm screw to keep the pivot from sliding out, though this can be optional.