Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:2986613.

i made my gb22 v7 so that the barrel can withstand more force from the slamming of the slide into it. the frame area where the barrel goes on is very tight and practically fused during printing but with a razor i was able to free it up so that the top and bottom spring ends apart to get the barrel on. just dont forget to put the slide and its rubber band in first (or spring that goes into the hole in the slide).