I bought a Colt Double Eagle (double action in 1911A1 format) and the factory Colt mag (8 rounder) works fine. I have two MecGar 1911 mags and tried them in the Colt. All three mags appear to look exactly the same. However, the 2 MecGar mags will not insert into the pistol grip UNLESS I press the mag. release button, hold it down, and then insert the Mecgar's. WHATS UP?????? Am I limited to ONLY Colt mags?