I have two dbls, one a J P Clabrough (British), the other a J P Sauer (German). Both of these guns are back action sidelocks & have dbl underbolts & a Doll's Head & are over 100 yrs old. The point of these, though is that neither have wear compensating bolts. The bolt notches & the bolts themselves are simply cut on a horizontal plane, paralell with the bbls. Both are on face & lock tight with the top lever centered. The top lever centers whether bbls are on or off & would appear it always did, was made to do so.
"Do You Reckon" that building in wear compensation "Causes" increased wear??
Should this gun have the top lever held back or snapped??
I say snapped because there is no lever latch, the lever returning to center as bbls open. The bolt is cammed back by the rear curve on the forward lug. As the bbls seat firmly against the frame the bolt clears the lug & snaps into the notch with virtually no contact (Friction). If one tried to hold the lever over & ease it down they would also undoubtably relax their hold on the bbls & their weight would put upward pressure on the lug causing friction on the bolt all the way down.
Smoke that one over you lever riders!!