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Could some one tell the the correct measurement for cylinder gap (min to max) and how the check cylinder gap and end shake? Also need the min and max for end shake. These are for large frame 45 LC Vaqueros Thanks

Well, I'm not a professional gunsmith by any means but from what I've learned over the years, it boils down to what you're going to be using your guns for. If you're shooting strictly jacketed bullets, you can go with tighter end shake and barrel/cylinder gap, say a couple of thousants on end shake and 3-4 on b/c gap. Depends on your powder also, as a clean burning powder will do better with the tighter settings. But if you want a study diet of lead bullets, it needs to be a little looser, particularly on B/C gap, due to typical lead buildup, maybe up to 6 thousants there. If you're into black powder, particularly the real stuff, not substitutes, then a lot looser, maybe 5-6 on end shake and up to 10 on b/c gap. As far as measuring it, force the cylinder back towards the recoil plate as far as it will go, stick a feeler guage that just goes in, between the gas ring and cylinder frame and that's the end shake measurement. Then, put another feeler gauge between the cylinder and barrel that just fits and that should be the b/c gap. Hopefully some real gunsmiths will chime here if I'm too far off.
HH

Go to alphaprecisioninc.com and read what one of the top pistolsmiths in the country has to say. He re-built my 5.5 inch SUPER tightly and it stays a lot cleaner with cast boolits. Guesstimate of 30-to-40 THOUSAND rounds through it over 10 years. (The hammer or hammer pivot pin is worn to the point of being able to push it slightly sideways...got to strip it down and check and repair OR install all new parts and get another trigger job.) I've been shooting the Original Size 44 magnum VAQUEROS pretty exclusively for the last six or seven years, but the old SUPER still out shoots my abilities...and remains a favorite.

With the front of cylinder and barrel face clean,
Hold the cylinder tightly to the rear and using a set a automotive feeler gauges find the thickest one you can insert between the front of the cylinder and barrel face. This is the cylinder gap.
Now hold the cylinder tightly to the front and find the thickest one you can insert between the cylinder and barrel with minimal force-friction.
Subtract the second figure from the first and you have the endshake measurement.
B-C gap is best between .004 and .008. Too much less and the cylinder will start to drag on the barrel after the shooting debris starts to build up. Too much and you'll start to loose velocity.
Endshake is best between .002 - .005. Any less and again the gun may start to bind up when it gets dirty. Too much can start to introduce light strike mis-fires and other timing related issues.
Sal