It should work with any standard 9mm bolt carrier group. Please email us at techsales@opticsplanet.com with 9mm bolt carrier groups you have attempted to use with these magazines as Mean Arms specifically states:
"The new EndoMag is a magazine insert that converts your Gen 2 or Gen 3 5.56/.223 PMAG® housing into a 9mm magazine to use with a standard AR lower and 9mm upper of your choosing with a Glock or Colt variant 9mm BCG"
I tried this with a gen 2 Pmag with an Aero Precision AR upper a Trybe defense 9mm BCG with the Trybe Defense 10.5" 9mm barrel, using a PSA lower, 6.5 oz 4" buffer and red Springco buffer spring and it worked well. Shot all 30 rounds and locked back.
I tried this with a gen 2 Pmag with an Aero Precision AR upper a Trybe defense 9mm BCG with the Trybe Defense 10.5" 9mm barrel, using a PSA lower, 6.5 oz 4" buffer and red Springco buffer spring and it worked well. Shot all 30 rounds and locked back.