Another possibility: your bolt lug may not be protruding enough to reliably grab the hammer and pull it back. You noted cutting it shorter because it 'came through the other side', but maybe it only needed to be backed off a bit from fully screwed in position.Don R.
You do not have to oil the bolt, but if you want to you can put a little lubrication on the bolt, just use a little of the ND10W-30 or secret sauce...etc oil that you'll be using for the pump cup.