Cheap, Quick Revolver Check

A quality revolver is a very useful firearm that with proper care can last the life of its owner and beyond. I have always appreciated a good revolver, having begun my handgunning career in my preteen years with a Smith and Wesson Model 27 .357 Magnum. I tend to prefer older, used revolvers because most of them were built to higher standards than today's new revolvers, where quality takes a back seat to lawyer-proofing. When I buy a used revolver, I don't mind a bit of honest exterior finish wear so long as the working parts are within specification. But there are a few things I like to check on a used (or even new, for that matter) revolver to make sure I will be getting my money's worth if I buy it. The main things I check are timing, barrel-to-cylinder gap, chamber throat diameter, forcing cone diameter, and headspace. To check these things I like to carry along a few basic tools that will fit an a pocket. In fact, it is a good idea to pack all of these items into a small pouch, along with an oil-soaked cleaning rag to wipe any residue, dust etc. off the revolver before checking it. These items can all be bought for less than ten dollars total, and include the following:

•  Small flashlight. One of the tiny LED lights powered by a coin cell will suffice, as will any cheap, disposable penlight or any other pocket-size flashlight.
• Blade-type feeler gauge. You can get these at any auto-parts store for around five bucks or less. Make sure it has, at minimum, a 0.008" (eight thousandths) blade. In fact, you could get by with just that one blade if you want to minimize weight and bulk.
• A bullet of the correct size for the revolver in question. Note I said a bullet, not a cartridge. Sorry to be so blunt, but if you don't know the difference, learn more about guns before you buy one. If you are looking at a revolver at your local gunshop and you pull out a loaded round, the proprietor is very likely to draw his own, loaded gun. I would. Besides which, a loaded round won't work very well for this test. The bullet can be jacketed and of nominal groove diameter of the revolver in question (.357 for .38 Special and .357 Magnum, for example) or cast lead and a thousandth over nominal (.358 for .38 or .357).
• Two hex or Allen keys, in the sizes of 1/16-inch and 5/64-inch.

When you are looking at a revolver and decide you are interested enough to check it out further, the first thing to do is ask permission by saying something like, "Do you mind if I check the clearances?" I do this while pulling out my small tool kit. That way he can see that my tools are not likely to damage the revolver and do not include screwdrivers or any other tool with which I might actually disassemble the gun. I might even quickly reassure the proprietor or salesman that I don't intend to take anything apart. In the unlikely event that the seller refuses permission to check the clearances, I would probably lay the revolver on the counter, thank him for his time, and leave immediately. But the chances are very good that you won't encounter this problem, so having secured permission, here is the procedure I use:

1. Swing out the cylinder (or open the loading gate, in the case of a single action revolver) and check that all chambers are unloaded. Wipe the metal parts of the revolver with your cleaning rag, paying special attention to the front and rear faces of the cylinder, the breech area, and underneath the extractor star. Close the cylinder.
2. Grasp the cylinder and move it fore and aft. There should be little to no discernible movement.
3. Point the muzzle skyward and grasp the handle in your palm, with your thumb near the trigger. Cock the hammer. Pull and hold the trigger fully to the rear with your thumb, while controlling and lowering the hammer with your other hand. While continuing to hold the trigger to the rear, shine the flashlight into the muzzle and make sure the chamber aligns with the bore. If it doesn't, you will see a crescent of the cylinder face on one side or the other. If you see that, the revolver has timing issues and should be passed over. While continuing to hold the trigger back, rock (rotate) the cylinder from side to side. There will usually be some movement, but it should be minimal. Now release the trigger, cock and lower the hammer to bring up the next chamber, and repeat the process for each chamber.
4. With the cylinder closed, point the muzzle at the floor. Cock and lower the hammer and hold the trigger to the rear. Insert the 0.008" blade of your feeler gauge through the gap between the cylinder face and the forcing cone (rear of the barrel). If it fits easily and with no drag, walk away. This revolver needs major work. If it fits but drags, it is at the outer limit of acceptability. I would still probably pass on that one, especially if the dealer has more revolvers like it. Ideally you want a 0.003" blade to fit, but a 0.006" blade to not fit; but a 0.006" fit with drag is still quite acceptable. The larger this gap, the lower the velocity with a given load; but it needs at least 0.003" clearance to prevent binding from firing residue and heat expansion. Repeat this test with all chambers.
5. If you noticed significant fore-aft movement (end shake) in Step 2, you can check it like this: with the hammer down and your finger off the trigger, measure the barrel-to-cylinder gap (as in Step 4) of one chamber while pulling the cylinder to the rear. Then remove that blade and measure the gap while pushing the cylinder fully forward. Subtract the first measurement from the second; it should not exceed 0.004" (four thousandths).
6. Open the cylinder, or remove it if the gun is a single-action. Insert the bullet lightly into the forcing cone. It should enter partially but not fully. If you can easily insert the bullet until its base is flush with the rear of the barrel, the forcing cone (and hence the barrel) is worn out. Now insert the bullet into each chamber throat in turn. A jacketed bullet should just slip into the chamber throats with no effort, but it should not be loose. A lead bullet should be a tight fit.
7. Lastly, the headspace. Most people don't even check it on a revolver, but overly generous clearance here can cause misfires, reduce velocity and accuracy, and if you reload, cause your cases to wear out prematurely. The rough test is to just use the 5/64-inch Allen key. That is 0.07825" across the flats, and if you can insert that between the rear of the (unloaded) cylinder and the breech plate while holding the cylinder forward, the headspace is well beyond acceptable limits and needs a complete rebuild at best. For most common revolver cartridges, minimum headspace is 0.060". Maximum is 0.070" for magnums and 0.074" for non-magnums. That holds true for .38 Special, .357 Magnum, .44 Special/Magnum, and .45 Colt. If you are checking anything other than those, I suggest you look it up on the SAAMI website. Ok, assuming the 5/64 didn't fit (if it did, forget that revolver), try the 1/16-inch key. That is 0.0625" across the flats and about 0.069" across the points. If it will almost but not quite fit, it may still be right at the minimum headspace. That is actually a good thing. Your feeler gauge may have the right combination of blades to allow you to determine within a thousandth or so what the headspace is. If the 1/16-inch key fit, try gently turning it. As long as you can feel contact on both sides (cylinder and breech) as you turn it, it is within spec. Note that this doesn't apply to any revolver whose chambers are recessed to accept the case rim, like early Smith and Wesson Magnums. On those guns you will have to use a feeler gauge. 0.020" would be maximum, 0.010" preferable, and no minimum so long as the cylinder will close and rotate.

Once you have finished these tests, you know much more about a particular revolver than you did before. This should enable you to make an informed decision on whether or not to buy it.&nbsp