mag is dropping from the rear by the mag release, i am 100% sure that the horn is locking into the front. im thinking the problem is to do with the mag release or the action of the bolt knocking the mag loose, and yes i am loading the mag with the bolt in the open position lol.
Like my IT buddies at work would say have you tried turning it off and back on again lol.
LOL...ok just checking.
If it's dropping from the back, then it's a release issue. Are you using the plastic or the metal pro-mag? If it's the metal one, is the latch tang on the back straight? Can you take a side view picture of your mag?
There's only two possibilities if the rear is dropping out. Either 1- the tang is bent upwards, creating a negative engagement angle with the magazine catch, or 2 - the magazine catch spring doesn't have enough tension (broken, missing, weak, full of cosmo, etc)