Confederate: note that the 18-20K rounds I have shot were in the 640--i.e., the SS 357 j-frame, not an airweight.
The vast majority--perhaps 75%--of these were rounds testing various powders and bullets built to "GDSB 38+P standards"--e.g., up to about 900 fps (2" barrel) with a 135-gr. bullet. Another 15% or so are testing variants of "the FBI load"--a 38+P 158-gr. round built to run about 800-820 fps from a 2" barrel. Another 5% or so were testing loads of what I call an "FBI900"--pushing a 158 gr. LSWC-HP to about 900 fps, built in a 357 case. Finally, I did do some 357 reloads testing various powders--notably, Ramshot's
Silhouette--all the way up to max powder recipes.
In summary, probably less than 2% of the rounds fired were at pressures over 30,000 PSI, I would guess. That "vast majority" were in the 14,000-22/24,000 range. I am no revolver expert, but to my eye and examination in cleaning, there is no significant wear. On an Airweight, with its usual aluminum frame, I'll bet there would be noticable stretching.
[At about round 300, S&W also fit a new cylinder to this gun following the firing of five overpressure rounds (about 18-gr. of AA#7 under a Speer 135-gr. JHP; I reported the incident for discussion here, in an old post). Upon return, the barrel-cylinder gap was at .005. It remains at that now, with some endshake. The trigger is a j-frame delight, of course, especially in the afternoons....
]
But, you've got my curiosity up: I'm gonna read up in my Kuehnhausen (sp) manual to see if I can measure it up myself some.
Jim H.
