[Hugh]

Mike,
Hate to be contrary to what Frank says, but sounds like a weak recoil spring to me. If it wont close when the mag is full or 1/2 full, when the mag spring is exerting the most pressure against the bottom of the toggle, then works ok when only a couple of cartridges are left in the mag, when the mag spring is exerting less pressure on the bottom of the toggle, then it needs a stronger recoil spring to close completely against the stronger mag spring pressure.