A300 mag tube extension

This is a mag tube extension for the Beretta A300; it adds one 2¾ shell capacity. You will need a new spring for this to work properly. I made mine out of ABS, and it's held up really well. You'll need to remove the plastic spring cap inside the metal mag tube. The threads should be a little tight but not so tight that you can't do it by hand. If you're having issues, try scaling it accordingly or increasing your print resolution. I tried to match the stock look as much as possible and think I did a pretty good job.

I also included a step file in case you want modify it. you could pretty easily stretch this design to make it hold more.