Working on the repeater problem with a .221fb cz mag inserted into a savage "sleeve." Will mill bottom metal and post a photo if it works. Here's the beginning, looks promising and feeds through the action. Haven't gotten the barrel so cannot tell if this will work. Donor is a 11gcns .223.

The assembly latches just as a stock one even before adding bottom metal. Will have to tweak alignment of cz mag held tightly inside sleeve. As of now, the feed lips of the sleeve hold the other mag just about right. Then add adhesive filler. (Stole ideas from members Dave and Randy , thanks for the help guys)! These are dummy loads of vartarg with 40gr.