|Revolver "guts" (Source: "A Critical|
Look at Revolver Accuracy
and Reliability"--Lucky Gunner).
Debris Under The Extractor Star:
An included article from Caleb Giddings at Gat Daily suggests that one of the most common causes of revolvers jamming is debris under the extractor star. Giddings states that "[s]omething so small as a flake of unburnt powder under the extractor star can suddenly make your revolver impossible to shoot, and it’s a failure that’s happened to me at least three times that I can recall. The fix for this is to take a toothbrush and brush out under the extractor star, which is a lot more complicated than a simple 'tap rack bang' drill." It doesn't have to be a flake of unburned powder, but could be sand or dirt, or even a heavy buildup of carbon. I've never had this issue in my many years of shooting revolvers (knock on wood) but I have had a few other jams.
Backed Out Ejector Rod:
I would say that most common problem I've had with the cylinder jamming so it won't turn or only turns with difficulty is because of an ejector rod that has loosened or backed out. For those unfamiliar with this part:
The ejector rod runs through the center of the cylinder and acts as a fixed axis allowing the cylinder to turn. The extractor is attached to the end of the ejector rod and is recessed into the cylinder. When the revolver is loaded, each cartridge rim rests against the extractor. After the last round is fired, the cylinder release is pressed and the cylinder swings out to the side. The shooter then pushes back on the front of the ejector rod. The rod travels back, catching the rims of the spent cartridges on the extractor. The extractor forces all the spent cartridges from the cylinder at the same time. The extractor is spring-loaded and returns to the forward position to allow for reloading.
If the ejector rod loosens or unscrews slightly, it will put additional pressure on the ends of the rod. I don't know if this pressure is limited to just the front of the rod and the locking detent, or also includes the ejector star to the rear of the cylinder, but the effect is to make it more difficult to unlock the cylinder to open it and/or to make it more difficult to rotate the cylinder. The solution, once you have opened the cylinder, is to tighten the ejector rod.
The first challenge to correcting this problem is getting the cylinder to open. You have to be careful to not bend or otherwise damage the extractor rod. The Revolver Guy explains what to do:
The first step in fixing the backed-out ejector rod is opening the cylinder. If the gun isn’t locked up too hard, you can probably get it open like I did, with a firm smack from the heel of your hand (while depressing the cylinder latch, obviously). This isn’t the preferred technique unless you are in combat, however. Smacking the cylinder open risks bending the ejector rod. The better way to get the gun open is to tighten the rod enough to unlock the action. This will require holding the ejector rod in place while rotating the cylinder, and rotating the cylinder requires freeing the cylinder stop.
At this point we should cover some safety stuff. Freeing the cylinder stop MAY require partially cycling the action by slightly pulling the hammer – or trigger – back (it was necessary in my case). It also may not. Try to shim the cylinder stop by inserting a thin piece of material between it and the cylinder. A business card works great for this purpose. If there is not enough clearance for the shim, or if the cylinder bolt just keeps chewing up the business card (as was my experience) follow the instructions below:
IF THE CYLINDER CONTAINS LIVE AMMUNITION, USE EXTREME CAUTION! FIRST, MAKE SURE YOU HAVE EYE- AND EAR-PROTECTION ON. ENSURE THE FIREARM IS POINTED IN A SAFE DIRECTION AND ALL OF YOUR BODY PARTS (AND THOSE OF FRIENDS, FAMILY, BYSTANDERS, NEIGHBORS, AND PETS) ARE CLEAR OF THE MUZZLE. NEXT, CONTROL THE HAMMER, IF YOUR REVOLVER HAS ONE THAT IS EXPOSED. IF YOUR REVOLVER DOES NOT HAVE AN EXPOSED HAMMER, CONTROL THE CYLINDER, AND RELEASE THE TRIGGER AS SOON AS THE CYLINDER IS FREED.
Once the cylinder is freed, insert a shim between the cylinder and the cylinder bolt. This will allow the cylinder to spin freely. Once you can turn the cylinder, you have to arrest the ejector rod. This is best done with a non-marring instrument. I have found that a No. 2 Pencil eraser works pretty well for this task. If you are using a S&W revolver manufactured after 1961, the thread on the ejector rod is a left-hand (reverse) thread, so keep this in mind. Figuring out which way to turn things can be the trickiest part of the whole operation.
If you are at the range and lacking other tools, you can simply tighten it as best as you can using your own hand strength pinching the ejector rod between your thumb and forefinger on one hand and using your other hand to hold the cylinder in place. This is just a stop-gap measure.
If you have pliers allowing you to get a better grip on the extractor rod, you will be able to better tighten it. The Revolver Guy explains:
Fixing this issue is relatively painless if you can get the cylinder open. Once you have it open, remove any live ammunition. Reinsert at least a couple of pieces of brass to support the extractor star when you apply torsion. This isn’t strictly necessary, but I’ve heard it recommended frequently, and I can’t think of a good reason not to do it.
Next, you will need some pliers to tighten the ejector rod. You will want to pad the jaws of the pliers for two purposes. The first is to prevent scratching the ejector rod. The second is to provide a natural “clutch” that will slip and prevent you from overtightening and stripping the fine threads of the rod. Though most forums and blog posts recommend leather, I didn’t have a scrap piece of leather on hand. I found that the cuff of a flannel shirt worked just fine.
He also has some suggestions on opening the cylinder, so be sure to read the whole thing.
Backed Out Bullets:
Another way you can have a revolver jam is if a bullet backs out of its casing far enough to jam the bullet up against part of the frame or forcing cone as the cylinder turns. It is not dissimilar to jamming a penny or two between a door and a door jam to "lock" a door shut. Although this can happen in theory to any caliber or loading, it is more likely with powerful magnum loads; and, in fact, I've seen it most often with .357 Magnum loadings.
The cause is basic physics. That is, as you may remember from Newton's first law of motion, an object that is at rest stays at rest unless acted upon by a force. This tendency to stay in place is the object's inertia.
In the case of a revolver, what happens is that as the gun recoils, the inertia of the bullet makes it want to stay in place while the firearm (including the brass case) moves backward under the recoil. This tendency of the bullet to remain in place is generally overcome by the friction between the bullet and the case wall as well as the crimping of the case into the bullet. But if the crimp is too light, and you are shooting a heavy recoiling weapon, you can have a bullet start to work its way out of the case a bit each time the weapon is fired. If the bullet works it way out far enough, it will jam up against the frame or forcing cone as the cylinder turns. At best, this means that you won't be able to turn the cylinder until you have removed the problem cartridge; at worst, you also will have problems with opening the cylinder.
The easy fix for this is to open the cylinder--if it is being stiff, one or two raps from a soft mallet will generally suffice--and remove the offending the cartridge. More problematic is determining whether this is a one-off problem or something endemic to the batch of ammunition you are using. I've seen this with both factory loaded ammunition and handloads, but it is more likely to be a problem with a batch of ammunition if it is handloads. If that is the case, you will want to go back through the batch and put a more positive crimp on each bullet.
Poor Lubrication Or Cleaning:
Poor lubrication and/or cleaning can cause problems with rotating the cylinder to the next shot. While your first thought might be a lack of lubrication to the internals of the revolver, my experience has generally been that it is due to a lack of lubrication of the ejector rod or something gumming up between the cylinder and the rod on which it rotates. That is, if there is no lubrication between the cylinder and the cylinder rod/ejector rod, and the firearm gets hot causing expansion of the metal or you get carbon buildup, it will become more and more difficult to turn the cylinder. The solution to this is to lubricate the rod.
Failure To Fully Allow The Trigger To Reset:
Although not a jam, per se, it might as well be. Grant Cunningham has a great article on this topic. Basically, however, in order for a revolver to reset the trigger must be let out fully before attempting another double action pull or manually cocking the hammer to fire. Failure to do so can lead to the mechanism not resetting so it can advance the cylinder or, as Cunningham mentions, could potentially cause the mechanism to completely lock up. I find that I'm more likely to do this when I've been shooting semi-auto regularly, but haven't been practicing with a revolver; probably because with many (most) semi-auto pistols you do not need to let the trigger out all of the way for it to reset before taking the next shot, and this carries over to when you try to quickly shoot multiple shots from a revolver.
Ellifritz also linked to an article describing a low round count revolver class where a third of the revolvers were unable to make it through the class because of breakages or malfunctions. It mentions other problems that can show up with revolvers, especially under a lot of stress such as from strings of rapid fire or, even, excessive dryfire. There is always the problem of screws loosening or parts wearing that can affect the timing and cylinder lock up. Timing issues can develop over time from a worn cylinder stop, ratchet or hand/pawl, or, in what was probably the case with the first revolver described in the foregoing article which had the side plate shoot off, a loose plate allowing the internal parts to get out of proper fitment.
It is enough of a problem that Caleb Giddings, writing for Shooting Illustrated, found it worthy of two articles to relate that the new Colt Python was able to make it through a 2,000 round shooting challenge without a breakage. (See Part 1 and Part 2 or his article). As Giddings explains:
A little known fact about revolvers is that the power of the ammo is only part of what wears them out. Everyone knows to not slam the crane shut on a wheelgun, but did you know that fast double action firing (or dry firing) can also accelerate wear and send revolvers out of time? In fact, chasing fast splits (the time between shots) has probably killed more DA revolvers than all the hot magnums in the world.
During rapid dry- and live-fire, the entirely mechanical action of a revolver has parts coming in and out of contact with each other at higher speeds than "normal" operation. To put this in an easy to understand perspective, you'll wear a car out a lot faster by accelerating to 100 mph and then stopping to zero over and over than you would cruising at 60 mph on the highway.
Consequently, I would recommend periodically going over your revolver to identify and tighten down loose screws or tighten the ejection rod and check the lock up of the cylinder.
This article is not meant to disparage revolvers. Obviously revolvers will not have feeding and operational problems from underpowered ammunition, bent or damaged feed lips, and so on, as can happen with a semi-auto pistol. I have had far more operational problems with my semi-auto pistols than with my revolvers, and so I do consider revolvers to generally be more reliable than a semi-auto. But if you do have a problem with a revolver, it will typically be much more difficult and time consuming to resolve than a semi-auto.