to be fixed. (When you get an estimate, if the armorer or gunsmith says you need a new ratchet, get a second opinion. Maybe five out of six times, all the gun needs is to have a new cylinder hand stoned to fit. Replacing an extractor is at least four times as expensive.)
Do all that again, and this time, once each chamber locks into place, wiggle the cylinder. If there’s a lot of slop and play, there’s a good chance that perfect chamber/bore alignment will be a chancy thing, and accuracy will suffer. This is generally a sign of bad workmanship in a cheaply made gun, and excessive wear in one of the big-name brands.
With magazine removed, hammer cocked, and safety off, the trigger is pulled on an empty Browning Hi-Power. Hammer does not move, demonstrating that magazine disconnector safety is functioning as designed.
In a test that will make you cringe, unloaded pistol begins at slidelock with finger on slide release lever…
…and the hammer remains cocked as the slide slams forward. This shows Kimber Custom .45’s sear mechanism to be in good working order. However…
…if the hammer had “followed” slide to the half-cock position as replicated here, gun would need repairs before being worthy of purchase.
A less abusive test for hammer-follow on an auto is to hold it as shown and repeatedly flick the hammer back with the free hand thumb.
Push the cylinder back and forth; front to back and vice versa. A lot of slop means excessive headspace. Particularly with a big-bore or a Magnum, it may be a sign that the gun has been shot so much it’s approaching the end of its useful life. A good gunsmith can fix this with some cylinder shims, however.
Check to see if magazines insert and drop out cleanly. This HK USP40 Compact passes the test.
Get some light on the other side of the gun, so you can look through the gap between barrel and cylinder. Hold the hammer back with your thumb until the bolt drops, and then rotate the cylinder, watching the gap. If you examine enough guns, you will find some that actually touch the forcing cone of the barrel. This is unacceptable; the cylinder will bind, the trigger pull will become uneven, hard, and “grating” as your finger works to force the cylinder past the bind point, and eventually the gun will lock up and stop working. On the other end of the spectrum, you may see a barrel/cylinder gap so wide that you could probably spit through it without touching metal. You can expect poor accuracy and nasty side-spit from such a gun. Reject it unless the seller is willing to pay for the repairs to bring it up to spec.
If the cylinder comes closer to the barrel on some chambers than others, the front of the cylinder is probably not machined true. Most experts would pass by such a revolver.
Autoloaders
With any autoloader, double check that it is empty and keep the muzzle in a safe direction. Try the action a few times. When you rack the slide, everything should feel smooth. The slide should go all the way into battery – that is, all the way forward – without any sticking points that require an extra nudge. If the gun binds when it’s empty, you know it’s going to bind when the mechanism has to do the extra work of picking up and chambering cartridges. If the gun is clean and is binding, pass it by.
Make sure magazines go in and out cleanly. Some guns (1911, for example) are designed for the magazines to fall completely away when the release button is pressed. If the test gun won’t do this with new magazines that you know are in good shape, there could be some serious warpage in the grip-frame or, more probably, something wrong with the magazine release mechanism.
Some guns (early Glocks, most Browning Hi-Powers, any pistol with a butt-heel magazine release) can’t be expected to drop their magazines free. However, the magazine should still run cleanly in and out of the passageway in the grip frame.
You want to check the sear mechanism with a hammer-fired pistol to make sure there won’t be “hammer follow.” The test itself is abusive, and you want to make sure it’s OK with the current owner before you do it. Insert the empty magazine and lock the slide back. Making sure nothing is contacting the trigger, press the slide release lever and let the gun slam closed. Watch the hammer. If the hammer follows to the half-cock position or the at-rest position, the sear isn’t working right. Either it has been dropped and knocked out of alignment, or more probably, someone did a kitchen table trigger job on it, and the sear is down to a perilously weak razor’s edge. Soon, it will start doing the same with live rounds, which will keep you from firing subsequent shots until you’ve manually cocked the hammer. Soon after that, if the malady goes untreated, you will attempt to fire one shot and this pistol will go “full automatic.”
Because the mechanism was designed to be cushioned by the cartridge that the slide strips off the magazine during the firing cycle, it batters the extractor (and, on 1911-type guns, the sear) to perform this test. However, it’s the best way to see if the sear is working on a duty type gun. (Most target pistols have finely ground sears and won’t pass this test, which is yet another reason you don’t want a light-triggered target pistol for combat shooting.) If this test is unacceptable to the gun’s owner, try the following. Hold the gun in the firing hand, cock it, and with the thumb of the support hand push the hammer all the way back past full cock and then release. If when it comes forward it slips by the full cock position and keeps going, the gun is going to need some serious repair.
Checking the manual safety/sear engagement on a 1911. First, cock the empty gun, put the manual safety in the “on safe” position, and pull the trigger firmly as shown…
If the pistol has a grip safety, cock the hammer of the empty gun, hold it in such a way that there is no pressure on the grip safety, and press the trigger back. If the hammer falls, the grip safety is not working.
If the gun has a hammer-drop feature (i.e., decocking lever), cock the hammer and drop a #2 pencil or a flathead Bic Stik pen down the bore, with the tip of the writing instrument pointing toward the muzzle. With the fingers clear of the trigger, activate the decocking lever. If the pencil or pen just quivers when the hammer falls, the decocking mechanism is in good working order. However, if the pen or pencil flies from the barrel, that means it was hit by the firing pin. You’re holding a dangerously broken gun, one that would have fired the round in the chamber if you had tried to decock it while loaded.
…now, remove finger from trigger guard…
Now, to test the firing pin, we’ll use the Bic Stik or the #2 pencil again. This time, we’ll pull the trigger. If the writing implement is launched clear of the barrel, you have a healthy firing pin strike. If it isn’t, either the firing pin is broken or the firing pin spring is worn out.
Caution: In both of the last two tests, wear