Advice Needed

[4 Scale]

I'm curious if you performed G.T.'s suggested test of firing the weapon with just one round, and verifying that the toggle locks open every single time? It is the first sentence of his post #47. G.T. helped me cure a '38 shooter of a persistent toggle operation problem, and this test was invaluable in helping us isolate the issue. You will have to do it enough to get good data - I would suggest 25 rounds, assuming it locks back every time. It is a great way to verify that the toggle mechanism is going all the way back with every round and (if successful) effectively eliminates a too-strong mainspring as the source of the issue. I think this test is especially important in that you reported the results of the tape test as inconclusive.