The top lever on my Cashmore hammer gun broke and I had to fit a replacement spring. Not being a gunsmith, I got the spring a little too tight so that gun is a little difficult to open because the lever has to be pushed a little harder than normal, but once that is done the gun opens easily. This does not sound like your problem which appears to be resistance to pivoting on the hinge pin or the extractors are not moving freely.

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BrentD, (Professor - just for Stan)
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