I did emags for ngrs years ago, like five for me n five for my eldest. It’s really easy to do bud. Just get a file and dremmel and tape measure. Cutting the top to the correct height; you just copy position of mag indent and work from that. The hardest part is taking enough material from the bb chute side so it doesn’t pinch enough not to feed, just steadily dremmel the corners off all the way up. To finish, cut a couple coils of the pmag spring, and that will keep tension on the base plate. You can put a small screw somewhere to keep the mag in place, but I never found this necessary as the fit was to tight. Once you have done one mate….