If you've been following this thread, you may have noticed that most of the potential malfunctions associated with DA revolvers involved problems related to reloading the revolver. (Debris under the extractor, a casing under the extractor, etc.) and that reflects reality.
A DA revolver is incredibly reliable when we’re talking about firing the capacity of the cylinder.
The mantra about the little snubnose revolvers providing “Five Shots for Sure” is a valid reality. The odds of being able to fire all the rounds in a cylinder without a failure are extremely good and the limiting factor there is the quality of the ammunition.
In fact, because the energy needed to operate the action of a revovler comes from the user and not the ammunition, even a complete failure of a cartridge to fire (a dud round) has no effect on the gun’s ability to function. You simply pull the trigger again.
However, there are some types of ammunition failures that are serious problems. The first is a bullet that is pulled from the casing by recoil and protrudes beyond the front face of the cylinder. This “prairie dog” type of failure where the bullet pokes out of its hole, will tie up the action. While this stoppage can be cleared easily with some time and maybe simple tools, it cannot be expediently cleared in the field, under stress. The key to survival here is to avoid this type of malfunction altogether.
Every time a revolver is fired, the live rounds in the cylinder that have not been fired are subjected to recoil. So, in a 6-shot cylinder, if you fire all the cartridges in sequence, by the time you get to the last round in the cylinder, that cartridge has been subjected to the recoil of the 5 prior shots. The inertia of the relatively heavy bullet resists movement while the casing is violently thrust rearward with each shot. The bullet is not being pulled forward, the casing is being pulled rearward. The details involving the direction of force aren’t terribly important here; the end result is the same – the force is working to separate the casing from the bullet. If the crimp is not sufficient to resist this force, the bullet will incrementally advance forward relative to the casing until it protrudes from the front face of the cylinder.
Now, this is a complete non-issue as long as the bullet is securely held in the casing until that cartridge is fired. That’s the job of the crimp of the case mouth. Generally speaking, this is a non-issue when dealing with good quality casings without defects (like a case mouth split) and proper crimps (either new factory loaded cartridges or correctly crimped reloads). Good quality cartridges will ride just fine in the cylinder until it’s their turn to go bang.
Highly unusual circumstances can cause problems even when good quality cartridges, with good crimps, are used. If the ammunition in a cylinder is only partially expended and the remaining live cartridges are constantly recycled through the cylinder without being fired, eventually the repeated recoil will pull the bullets from those unfired rounds. The scenario to set up that failure is rather bizarre and would likely require the user to intentionally and repeatedly recycle an unfired round through a cylinder but there is a factor that shifts the odds. That factor is an ultra-lightweight revolver. The extreme low mass of some guns such as the S&W Airlite models with their lightweight Scandium alloy frames and Titanium cylinders, make them effective inertia bullet pullers. That last cartridge in that 5 round cylinder will likely tolerate the ride of 4 recoil impulses just fine, but you may not want to subject it to that inertia bullet puller 8 or more times.
