I took a cheap 30rd mag I bought for like $13 and used some 550 to jazz it up. Marked off where I needed the cord and wrapped it. The 550 cord helped with movement in the mag and is now very tight. You do need to slap it to lock. Falls freely with mag release. Haven't taken it to the range yet but seems to cycle fine. Limp wristing the slide at this point when racking first round will cause some issue. Clean pull and release there is no issue. Does have a rattle I assume is the spring and parts. Bottom seems non removable.
May get a MADS if it will work with the mag for a little something more.