Here is what silhouette shooter using Freedom Arms 353 (large frame 357) told me; he was shooting 200 gr GC bullet over the top dose (we are talking about rifle pressure level!) of slow burning double base ball powders and he noticed erosion of barrel forcing cone. He switched to IMR 4227 and further erosion stopped.
One of the theories is that such erosion (excluding that nonsense of using 110 and 125 gr bullets trying to make 357 Swift) is the consequence of higher burning temperature some double base powders have. Other one is that some additives are creating such erosion/sand blasting effect on top strap and forcing cone Most likely all above when combined with very high pressure.
None of my revolvers have top frame flame cutting but I don’t push them too hard. Some very light marks yes, but I wouldn’t call it “cutting” after seeing the pictures what could be done on 357 maximum. Also, using steady diet of full power loads could create top flame cutting on any Magnum revolver; I had seen it on 357 and 44 magnums. If I have 357 Supermag, I’ll use 180-200gr bullets and single base powders like IMR 4227 and Hodgdon H4227 or slower. Important note; be aware that IMR 4227 and Hodgdon H4227 are NOT interchangeable. H4227 is the fastest of so called “Hodgdon Extreme” rifle powders, see
http://www.hodgdon.com/smokeless/extreme/page4.php . These powders are practically insensitive to the temperature variation, something that MUST be taken in consideration when reloading top level loads for 357 Maximum, see
http://www.hodgdon.com/smokeless/extreme/page2.php#top .
For a while, I was thinking of getting 357 Maximum SBH. There are few in my area gathering the dust in lockers. However, after considering my personal preference for Bisley grip, comparing ballistic charts and listening other silhouette shooters, I settled on 41 Bisley as the optimum caliber/revolver combination for practising. If I want a “boomer”, I load 45-325 at about 1150 fps, might try to reach 1200-1250 fps to see what kind of accuracy I am going to get. Just my personal view…