Take it to a gunsmith familiar with the SBH. Sometimes, you are just not able to see what you are looking at, and another pair of eyes is required. I have three SBH revolvers plus clones, and I have never encountered the condition you are describing.
Good Shooting Makes Good Hunting
Patron Member NRA;
Life Member RMEF, SCI, NSRPA, CRPA: Member, FTRF, HHI #7108, CBA