Tep;I had the sales person open a pac and I slid it in my BG380 It sounded cheep loading it in and the plastic felt really cheep,not as solid as the factory mag,she was a no go.
I have no direct experience with Triple K but a few weeks ago I asked about some 457 magazines by them. One of the answers was that they are more or less like Pro Mag. 'nuff said!