Some guns have pin retractor springs, others don't. They are not a necessity for smooth opening, but if a gun had them originally then they should be used, as the pins would be likely to have excess protrusion without them. A missing spring would mean more than .020-.030", but one broken could have the ends overlapping to account for this amount. With gun cocked & bbls removed what do the pins do. Are they retracted or loose in their holes? Most hard opening of this nature is from either mishaped pin ends or worn cocking mechanism not moving the hammers soon enough. If the pins themselves are sticking or binding in their holes, this can of course make for hard opening as well.
