Where to measure end shake

[MrBorland]

If the cylinder has a snug fit, say .002" end shake, but there is .020" behind the casing, then surely the casing is going to slide back and hit the frame with each firing.

Unless I’m missing something, this is precisely what’s supposed to happen. Upon firing, the case DOES slide backwards, and it’s this impact with the back of the frame that re-seats the primer. If you load an in-spec revolver with perfect endshake muzzle down, then raise it muzzle-up, you’ll hear those rounds fall back and “tink” against the back of the frame. As long as actual endshake (fore-aft movement) is within spec, all is ok.

It seems worth repeating: the gap at the front of the cylinder, between the cylinder and forcing cone, is what matters. Seems like your gap at the back of the cylinder is .095”, and you’re getting wigged out because you think 1) that gap ought to be zero (it shouldn’t- see above) and 2) adjusting it to zero transfers a .095 gap to the front, which is way too much. The first is wrong, as I explained above, and the second is a misguided approach to fixing the first. As mentioned, if the gap at the front of the cylinder IS .095”, you’ve got problems, and the gun needs to see a gunsmith.

 

[MrBorland]

So please tell me, am I being too particular?

Very possibly. If in doubt, take it to a gunsmith.

I’ve seen those videos, too. I’m betting many revolver shooter have too. Typically they are demonstrating the power of a magnum blast from a normal gap to draw attention to the danger of getting your thumb too close to the cylinder gap when shooting magnum loads. They’re not meant to demonstrate some kind of life-threatening blast from some enormous cylinder gap (between the barrel & cylinder).