[bruce]

Too much semi-only firing will do this. The spring loaded contact switch gets slammed backwards into the post every time it's in semi-fire mode. Much better for the mechbox if you do short burst on Full-auto mode. The switch doesn't get release to fly back into the post.

I've fixed several broken post with a 3/32 steel pin JB Welded to the mechbox. Just use a 3/32 drill bit to make a hole at the same location and glue the pin.