[Roundsworth]

I bought a $5.00 set of stainless feeler gages from my local auto parts emporium. The .004" leaf was just right for my 1877 Lifter. It brought it back on face and it now locks up like a bank vault! I may have been lucky, though, because other issues can come into play. The gap between the barrel flats and water table can be affected also. As long as you don't try to force the action shut with too thick a shim, you may be okay. Good luck. Cheers!