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Discussion Starter #1
I just read that when purchasing a used revolver aside from a borelight you should have "feeler gauges" in ".002 .004 and .006" Is this accurate? What are these? where would I purchase them?, and how exactly are they used?
How do you inspect a used revolver? Thanks.
 

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That's a pretty involved question. First ... feeler gauges (AKA gap gauges). Go to your local automotive store and buy a feeler gauge set. These look much like a pocket knife with many blades. Most have blade thicknesses from .002" to .030". You don't need an expensive Snap-On set, in fact a cheap $5 set will work fine.

There are three main things to check on a revolver no matter the brand or model. The gap between the cylinder face and the rear of the barrel is known as the B/C gap. On most DA revolvers, it should be at least .004" but less than .008" with .006" as optimum. A looser B/C gap will loose too much velocity and will "spit" particles. A tighter B/C gap can cause the cylinder to drag on the barrel when fouling builds up. B/C gap is measured by inserting the thickest blade that will fit with considerable friction between a clean cylinder face and the rear of the barrel.

Next is the cylinder endshake. This is the amount of forward/backward cylinder play and is calculated by first measuring B/C gap as above, then holding the cylinder forward and measuring B/C gap again to find the thickness that will fit with slight friction. The difference between the two measurements is endshake. You want about .002" but no more than .005". When endshake is more than .005", repairs are needed on the cylinder assembly.

Last is headspace. This is the distance between the head of a case and the firing pin bushing. To measure, place a new unfired case (not a live round) in the cylinder and rotate it until it is under the hammer. Wedge a blade in the B/C gap so the cylinder can't be forced forward. Insert the thickest blade that will fit between the case head and the recoil shield. This measurement should be no less than .008" nor more than .012" with .010" as optimum. An out-of-spec headspace measurement means the gun is worn or has been fired a lot with hot loads.

Inspect the forcing cone for a smooth transition from the mouth to the lands. Use a jacketed bullet and insert it in each of the cylinder throats (push the bullet in nose first into each throat from the front face of the cylinder). It should slide through with slight finger pressure. Use a small flashlight to inspect for proper cylinder-to-bore alignment. Dry fire and hold the trigger back while shining the light between the rear of the cylinder and the recoil shield. You should not see the edge of the cylinder when peering through the bore.

These tests will pretty much tell you the condition of the revolver. If any measurements or tests are not in spec, don't buy the gun or you may end up spending a lot on repairs.

Note: Most dealers will not let you do much more than a "visual inspection".
 
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