When installing the Bullgear Boxmag onto my Raven M249/M249 Featherweight I found that the feed block sits deeper than the standard a&k m249s. So to get the upper half of the box mag to line up with the lower, I found that you have to space the upper mag portion with velcro to match up the magazine properly.
Doing so creates a gap between the feedblock and the mag allowing jams so I made this shim to close the gap of the feedblock nozzle and the mag itself to eliminate jams.
blgear_v7.stl | 20.8KB |