Revolver malfunctions, Part One.
Monday, June 25, 2012 Filed in: Revolvers
I received an email last week, a sort of complaint that I don't write much about revolvers any longer. Well, I wrote an entire book - isn't that enough?? OK, OK, you win - let's talk about revolver malfunctions.
I've mentioned before, in more than one venue, that the revolver typically will have a longer mean time between failure than an autoloader (we're talking unique failures, which automatically discounts those due to ammunition problems - which can affect either platform equally.)
The usual response from the uninitiated is "well, I've seen revolvers fail too!" I've tackled this specific inanity before, but suffice it to say that there is a heapin' helpin' of confirmation bias at work in that type of statement. It's a grade school playground argument.
Still, there are failures that can happen to a revolver and it's important to understand what they are and how they can be prevented.
The possible failures can be classified in roughly decreasing order of frequency: 1) ammunition irregularities, 2) maintenance related problems, 3) user-initiated malfunctions, and 4) actual mechanical or design failures.
The last category, save for one specific case, is frankly quite rare with revolvers. Design and functional failures are more common with autoloaders, which is really my point: revolver malfunctions are avoidable to a greater degree than autoloader malfunctions.
Let's start at the top: ammunition failures usually boil down to high primers and squib loads, and both are almost always the result of handloaded ammunition. That isn't to say that they can't happen with factory ammo, only that I've personally never seen the case where they were. (I'm not going to talk about catastrophic over-pressure failures, those where the gun is destroyed, as they go well beyond “malfunction”!)
High primers can jam the cylinder rotation by taking up the small area between the case head and the breechface, and usually require a good "whack" to get the cylinder open. A high primer on an unfired round can be avoided by checking the ammunition before use (simply open the box and run your finger down the rows; a high primer can be easily felt.)
Those that occur after firing are usually the result of a too-light load. The primer is usually forced backwards out of the primer pocket by the pressure in the case, but normally the recoil of the cartridge against the breechface reseats the primer and allows it to pass. Light loads often will not generate enough recoil to do so.
Squib loads are the bane of revolvers and autos alike, as they can result in severe damage to the gun. A squib is a load with an insufficient (or non-existent) powder charge, which is insufficient to drive the bullet out of the barrel. Squib loads are always a possibility with any ammo, though I've never seen one that wasn't the result of handloading.
A squib which pushes the bullet into the bore but not clear of the muzzle is a danger if a full-power round is fired behind it. The least that will happen is a bulged (ruined) barrel; the worst is a catastrophic cylinder failure. Bullets lodged in the barrel occur most often with jacketed bullets and very light loads; jacketed slugs offer more frictional resistance than do plain lead, and need to be loaded to higher velocities to reliably clear the barrel. Jacketed bullets should never be used with light loads.
When the squib is the result of no powder at all the bullet often ends up stuck in the forcing cone with part of it still in the cylinder. This is actually the preferred squib, as the gun won't fire another round because the cylinder won't turn! This type of squib is easily rectified by tapping the slug back into the cylinder with a cleaning rod, then opening the cylinder and clearing the chamber.
Ammunition which does not burn completely, leaving powder flakes in the barrel and cylinder, can (and often will) cause a stoppage. The unburnt flakes can get under the extractor star, which keeps it from fully retracting. The effect is much like a high primer and is dealt with similarly. Unlike the high primer, this problem will recur immediately unless the extractor is cleaned, and repeatedly until the ammunition problem is sorted out.
If you’re a handloader, you should pay attention to your powder and be vigilant for unburned flakes. Sometimes this is a function of an insufficient crimp, so make sure that the rounds are firmly crimped. Some powders, however, just don’t work well in the low-density loads typically encountered with large revolver cases. The solution is to pick a powder that gives a higher load density or doesn’t mind low densities. This often means a slightly slower-burning powder, thought not always.
For instance, I’ve found that Hodgdon Universal Clays is a superb, clean-burning powder for the 9mm Luger cartridge (or any autoloading cartridge, actually) but will not burn completely in a standard-pressure .38 Special. (Don’t even bother with the .44 Special!) For that reason I switched to Alliant Red Dot for the Specials, which burns far more cleanly in the bigger cases. In fact, I’ve found all of the “Dot” powders to be very clean.
On Wednesday we'll look at user and maintenance failures.
-=[ Grant ]=-