Tuning Buckleys Modern pneumatic airgun trigger

[darkskyy]

Hey guys I'm trying to follow Buckley's book, the Modern Pneumatic Airgun vol 2. I'm to the part were the trigger needs adjusting. At times I can get it to strike the valve stem 10-15 times in a row, then the striker jams/locks up on the sear? Other times after reassembling it it will only fire a few times before jamming. I've been fiddling with it a bit but not really sure what I'm catching on, any help would be appreciated.

Thanks

 

[towle]

That title rang a bell!, bought vol 1 in 2004 so don't know if it is of the same design, but if so, could be a problem with the heel of the sear dragging on the hammer