Ok, I bought a new barrel and when i lock it up I have to rap the trigger guard on table edge to open it . Sorry I did not state it is a contender rifle. Several years ago I got some information on how to solve this problem , but 2 strokes and memory fails me as to what has to be polished ? Ok ,this is what i have done so far,dropped triger guard assemble and cleaned and lubricated,polished the top of lugs with diamond file and rounded part and sides.then lubercated them.the frame works fine with other barrels. But lugs feel lke they have a really strong spring. any help would be appreciated.