Q: from the shop I bought the Aero Precision AR 15 lower receiver (Texas Edition). I also bought 4 brand new Magpul magazines, They will not lock into the lower without a forceful slap on the bottom and will not release from the well with the push of the magazine release. I have to pull the magazine out awkwardly. I had 2 metal magazines that I use with my Colt AR 15 A2 and they lock and release as designed. Is the problem with my Magpul magazines or my lower receiver? Curtis@inbox.com