Join Date: Jan 2010
Location: South Central Wisconsin, USA
Shimming a cylinder forward can result in throwing the timing off as the hand may not full rotate the cylinder into lock position;
You have three issues, basic headspace, in this case the nipples/caps to the rear, the cyl/barrel gap to the front when the cylinder is held completely back and endshake. The basic Colt's type open top tends to have a fair amount of endshake, and needs it.
A)With the cylinder pushed full forward measure the clearance to the rear with a feeler gauge. You also want to note if the cylinder still has any cyl/brl gap at all, it needs at least .001".
B)Pushed full back measure the cyl/brl gap.
Subtract A from B for the endshake.
Ive had C&B revolvers with .010"+ cyl/brl gap that shot well and one with about .004 iirc that would bind up too quickly for me; even though specs are as previously noted as .004-.009 I like on the wider end for Black Powder (never did much with Pyrodex and nothing with the other 'substitutes'. Your .010-.012 wouldnt put me off at all.
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