Mod.12,
As a test, about 2 yrs ago, I set up 2 brass '60s with tight tolerances and the users were to shoot normal-max loads in them. One of them was a designated fanner (2 different owners. One here in the East, the other in AZ). As far as I know, they are still going strong! In fact, I just asked about the fanner a couple of months ago and it's still going strong.
In my experience, seems to be in how the revolvers are setup from the "get go". Whether steel or brass, a close tolerance revolver (especially an open top) shooting bp loads will hold up just fine. Allow sloppy clearances to develop ( usually as is from the factory) and the life expectancy is concurrent with the amount of slop. Cylinders will become slide-hammers (excessive/growing end shake); and beat the revolver apart, modern or antique design.
I did the same as Hawg with a brass Remington (NMA) I got in the '70s (college boredom). In the mid '80s (and after a lot of shooting over its life) the cyl had imprinted as well. While shooting one day, I bent the arguably "strongest " design while loading it!! I've never bent a brass open top loading it, or shooting it, . . . . . ever!
The open top design is an extremely strong design, it's the poor execution in the build of it that has "tarnished" (brass or steel!! Pun intended!!) it! Short arbors, misaligned bore/chambers, crappy action parts . . . the kind of things that are the detriment of "our" copies and the reputation of an elegant design.
Automobile engines of the '40s, '50s, '60s and '70s were junk if they even made it to 100,000 miles! The '80s saw great improvement (with Alu. blocks AND heads no less!!) and today, 100,000 miles is piece of cake!! (Mine and my wife's cars have had 3 pieces of cake! Each!!)
Close tollerances with a good design will win every time!!
Mike
www.goonsgunworks.com
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