The bolt is the handle you pull back to put a pellet in the gunWhen you pull the bolt slowly there is noticeable first click before the hammer is engaged.Pull it back about 1/8 of an inch and leave it there when you pump.I know that when you put a lighter spring in the valve you have to do this to be able to fill it with air.My 392 Steroid is the same way.A worn spring? Maybe.Try it and see what happens.