I have a Pro Team Products Generation 4 Micromag for sale. I have come to terms that I do not need 2 of these amazing markers.
Paint was good. Bounced at shoulder height and at room temp. My bolt spring is the short one. So I definitely at least need the medium one.
If any of the paint is odd shaped or is larger diameter at its widest point, then it often causes barrel breaks on paint with weak seams or fragile shells.