The Gun Digest Book of Combat Handgunnery. Massad Ayoob

seen from the muzzle end.

       Universal Examination Points

      As a general rule, a gun in pristine condition outside has probably been well cared for internally. This is not written in stone, however. Accompanying this segment are photos of a vintage Smith & Wesson Model 15 Combat Masterpiece .38 Special. It was found for sale among several others in a North Dakota gun shop in 1998, bearing a price tag of $130. Externally, what blue hadn’t been worn off had been pitted. It looked as if someone had left it out in a field for the last couple of years. However, when the buyer examined it, he found the bore to be perfect, and the action so smooth and in such perfect tune it felt as if it had just left Smith & Wesson’s Performance Center. He cheerfully paid the asking price, took it home, and discovered that it would group a cylinder of Federal Match .38 wadcutters into an inch at 25 yards.

      It can go the other way, too. One fellow left the gun shop chuckling that he’d bought a fancy, premium brand .30/06 rifle, without a scratch on it, for at least $300 less than what it was worth. Then he got it to the range, and discovered it was less accurate than a Super-Squirter. Only then did he check the bore, to discover it rusted to destruction. The previous owner had apparently burned up some old, corrosive WWII surplus ammo in the expensive rifle and neglected the necessary immediate cleaning chores. The gun needed an expensive re-barreling job.

       Testing a revolver’s timing. With the free hand thumb applying some pressure to cylinder as taking a radial pulse, the trigger finger starts a double-action stroke…

      Before you do anything else, triple check to make sure the handgun is unloaded. I have seen people work a firearm’s action at a gun show and freeze in horror as a live round ejected from the chamber. Don’t let your natural firearms safety habits grow lax because the environment is a shop or show instead of a range.

      Have a small flashlight with you, and perhaps a white business card or 3x5 card. (The Bore-Lite made for the purpose is, of course, ideal.) With the action open, get the card down by the breech and shine the flashlight on it, then look down the barrel; this should give optimum illumination.

       Testing for “push-off” with cocked Colt Official Police. Hammer stayed back, passing test.

       …and the cylinder has locked up tight even before the hammer falls, showing that this Ruger Service-Six is perfectly timed, at least for this particular chamber.

      If the bore is dirty, see about cleaning it then and there. The carbon could be masking rust or pitting. What you want to see is mirror brightness on the lands, and clean, even grooves in the rifling.

      Watch for a dark shadow, particularly one that is doughnut shaped, encircling the entire bore. This tells you there has been a bulge in the barrel. Typical cause: someone fired a bad load that had insufficient powder, and the bullet lodged in the barrel, and the next shot blew it out. The bulge created by that dangerous over-pressure experience will almost certainly ruin the gun’s accuracy. Pass on it.

      Try the action. If everything doesn’t feel reasonably smooth and work properly, something is very wrong with the action, and unless home gunsmithing is your hobby, you probably want to pass on it.

      Now, let’s branch into what you need to know about function and safety checks for revolver versus auto.

       Drawing the trigger or hammer back slightly to release the cylinder locking bolt, slowly rotate the cylinder to analyze barrel/cylinder clearance.

       Checking the Used Revolver

      Double check that the gun is unloaded, and keep the muzzle pointed in a safe direction. Check the bore and action as described above.

      If it has both double- and single-action functions, cock the hammer. Keeping fingers away from the trigger, push forward on the cocked hammer with your thumb. If it snaps forward, you’ve experienced “push-off.” This means either that the gun has had a sloppy “action job” done on it, or was poorly assembled at the factory, or has experienced a lot of wear. Since most experts believe a combat revolver should be double-action only anyway, and a good plan is to have the single-action cocking notch removed after you’ve bought it, this may not matter to you. Keep in mind, however, that it’s an early warning sign that something else might be wrong with the gun.

      With the cylinder out of the frame, spin it. Watch the ejector rod. If it remains straight, it’s in alignment. If it wobbles like the wheels of the Toonerville Trolley, it’s not, and there’s a fairly expensive repair job in its immediate future.

      Close the cylinder. Looking at the gun from the front, push leftward on the cylinder as if you were opening it, but without releasing the cylinder latch. Watch the interface between the crane or yoke, the part on which the cylinder swings out, with the rest of the frame. If it stays tight, the gun is in good shape. If there’s a big gap, it tells you that some bozo has been abusing the gun by whipping the cylinder out of the frame like Humphrey Bogart. This will have a negative effect on cylinder alignment and will mean another pricey repair job. A big gap in this spot always means, “don’t buy it.”

       The cylinder of S&W 686 is opened, then spun. Watch the ejector rod. If it wobbles, it’s out of line and may need replacement.

       The author drops a pencil, eraser-end first, down barrel of cocked and empty S&W 4506. Note hammer is back, and decocking lever up…

       …when the decocking lever on the left side is depressed the pencil stays in place. This shows that the decocking mechanism is working properly.

      With the cylinder still closed and the muzzle still in a safe direction, take a firing grasp with your dominant hand. Cup the gun under the trigger guard with your support hand, and with the thumb of that hand, apply light pressure to the cylinder. Use about the same pressure you’d use to take your pulse at the wrist. This will effectively duplicate the cylinder drag of cartridge case heads against the frame at the rear of the cylinder window if the gun was loaded.

      Now, slowly, roll the trigger back until the hammer falls. Hold the trigger back. With the thumb, wiggle the cylinder. If it is locked in place, then at least on that chamber, you have the solid lockup you want. If, however, this movement causes the cylinder to only now “tick” into place, it means that particular chamber would not have been in alignment with the bore when an actual shot was fired. Armorers call this effect a DCU, which stands for “doesn’t carry up.” You want to repeat this check for every chamber in the gun.

      When the revolver’s chambers don’t lock into line with the bore, the gun is said to be “out of time.” The bullets will go into the forcing cone at an angle. This degrades accuracy, and causes lead shavings to spit out to the sides, endangering adjacent shooters on the firing line. As it gets worse, the firing pin will hit the primer so far off center the gun may misfire. With