I had the same problem Colin, I figured out it was the cut off lever catching against the slide, so I sanded it down a bit to make a ramp so it no longer catches. I was told by Tys and other Hicapa regulars that this was the fix.
If you dont know what I mean, its the tiny lever on the top of the trigger block that the slide pushes down when it cycles.
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W1-5
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