I used to keep two shotshells in front of four slugs when I lived in an apt years back, but no more.
RCBS sells dies to make SS for the 45acp, which will cycle the gun. They must be used in a Colt clone, the Glocks wont set off the rifle primers. A 308 case gets cut down and reformed, then a 410 shotgun shell wad is lightly tamped down over the powder charge with a dowell, cut flush with case mouth, add some #9's and cap the ensemble with a single 00 buck. these loads throw a nice rabbit sized pattern at about 20-25 ft, and could certainly be used for defense with the 00 in there.
I like em' but it seems that everyone I show em to looks at em like thier the red headed step child or something???