Mr. H-4831, Bruce its been my experience that if you work up loads by half grain increments, until you get sticky extraction, then back off a half grain, you'll have a safe working load, providing none of your bullets weigh heavy, and provided you don't encounter a piece of brass that has a bit less volume. With cast bullets, it might be a good policy to segregate your bullets by weight if you're loading maximum loads. The heavy ones need a bit less powder. If you still occasionally have sticky extraction, your brass volume might be inconsistent, so back off another half grain. Your ejector rod is the best indicator you have of unsafe pressure.[/QUOTE)
I never did have sticky cases in a magnum revolver and I have had two 357 revolvers and five 44 magnum revolvers. I do note that I have it written in my notes that one time 14 grains of Hercules 2400 and 14.5 grains of H110 was too heavy with the Keith bullet, as the primers leaked. However, that is a better indication of soft primers than an overload. You will note that I used the caveat of no, "Reliable way," of judging pressure--.
As far as all going fine until one round suddenly blows the cylinder up, I can vouch for. I won't list every detail, but when we were young and foolish we were shooting factory cartridges in a quality revolver which was not designed for the heavier loads we were using. We must have shot over a hundred such rounds when one day I was shooting my usual one handed and K BOOM. And I mean B O O M, accompanied by a ball of fire surrounding the gun and my hand.
I have always treated them dang revolvers with a bit of extra caution ever since. We know we have a great amount of built in safety when building up a heavy load with a good bolt action rifle, but revolvers do not have that extra layer of built in safety, whatsoever.
If anyone should have had a good idea of judging pressure in a revolver, it would have been Elmer Keith. But he unintensionly blew up the cylinders on quite a few 44 Special revolvers in the course of developing the 44 magnum.
Its funny how those little incidents stay with us. I've developed a pretty low opinion of compressed loads thanks to the combination of a case full of Retumbo topped with a heavy bullet, which went from safe, with no signs of pressure to a wrecked rifle, having chucks of steel and brass plucked out of my eye with tweezers, and several weeks of being extremely light sensitive, with the increment of a single grain of powder! I don't think much of Quickload either, once the parameters of a load exceed the standard for that cartridge. For example if a 150 gr bullet is considered standard for the .30/06, approaching the Quickload prediction for a 240 gr bullet should be approached with great caution; no I didn't blow up my ZG-47. I now firmly believe that once a powder charge is compressed, the pressure resulting from any further incremental increase in powder, is no longer a representative percentage of the total volume of that cartridge.
In your case though I believe a chamber in you cylinder had a microscopic crack or perhaps the entire cylinder was improperly heat treated, as the incident is so far outside of my own observations. I did lots of stupid #### too, like loading .357 magnum loads in thin webbed .38 Special brass, but other than sticky extraction I never so much as suffered a cracked case, never mind a wrecked gun. Once the pressure is excessive, the web of the case expands, even with thick webbed magnum brass, and sticky extraction is assured. Thus I consider sticky extraction the signal to retreat, and a half grain of powder in a small pistol case makes for a significant change in pressure.
Back in the day when Elmer was experimenting with heavy .44 and .45 loads, he blew up some .45 Colt SAs, coming to the conclusion that the cylinder walls were too thin over the bolt cuts, so a .44 would be a better option than a .45. I don't think he ever managed to blow up a .44 Outdoorsman when working up heavy .44 Special loads, but I might be mistaken. I must say, that I was first a bit distrustful of the fluted cylinder of my .44 Ruger Vaquero, after my earlier Super Blackhawk, but I've fired a couple of thousand full powered loads though it now, without so much as a hiccup, however, I did load one batch of cast bullets without checking the weight, and I did have some sticky extraction due to variations of bullet weight and case capacity, but no gun issue.