Hi CF, I have had and tuned Lugers that would ONLY work with Winchester .30 ammo?.... and absolutely not work at all with any Fiocchi ammo.... Take the firing pin assembly out and cycle rounds thru by hand? If they cycle thru, it's not the clip.. it's the ammo, (under power or short OAL) or mainspring... I do ALL my testing with Winchester, even though it's expensive! .... Good luck, best to all, til...lat'r....GT