How do you measure barrel to cylinder clearance?

[oldfool]

frankly never heard of using snap caps or brass to check gap, prior to this thread
"rims in place...sets the limit on how far to the rear the cylinder can move."

Remllez
"Think about it....they would create such a drag as to be compared to the cylinder dragging on the forcing cone up front."
precisely !

DWFan
"can go as tight as .002" without problems as long as you keep the cylinder face clean."
yes... powder residue on face will show faint scuff marks if you look, but you will feel the cylinder drag first, if you do not keep it clean, so just keep it clean
some love it that tight, some hate it
me, I love it on one of my k-17s, but don't need it on all of 'em
depends on what you most like doing with the gun, of course
(another good excuse to own more than one anyway)

 

[Notoast]

If I use spent brass or snap caps, I get a different measurement (0.001 smaller) than if I use decapped brass or no brass (all with hammer forward, trigger back). I assume it's the firing pin pushing on the case?

 

[Shimitup]

Drail, that kind of baffles me that it would say that, as SAA suggested double check the manual to make sure he's not talking about a headspace measurement. If you've done what I suggested about holding it up to the light with muzzle down you can see what I mean about seeing a gap behind the case head. The revolvers I've worked on over the years S&W Ruger or Colt have been pretty liberal with their allowance for headspace. As Rcmodel alluded to, the rims can vary a bit in thickness.

 

[Drail]

I stand humbly corrected. Kuhnhausen was referring to a headspace check. Thank you for straightening me out. Sorry for the misinfo.

 

[Shimitup]

No sweat, easy thing to confuse. I find myself digging around in reference books way more than I used to to find out what used to be in my head, it's kind of annoying.