Turnbull recased a Charlin sliding breech action gun for me, better than a decade ago, I'm guessing. That gun appears in a photo in Double Gun Journal in the Darne piece I wrote. If there is an action that won't take ANY warpage, it is a Charlin, and Mr. Turnbull promised and delivered.
Had I seen various cracked Parkers, LC Smiths, Savage 5100, Iver Johnson Hercules, Ithacas, of any sort or, come to think of it, Tobins, a design, by the way, that I believe really should crack on occasion, since not all that much supports the standing breech under those lockplates, I would have posted that.
But, all I've seen are broken Foxs. Not just here, either. Now, I would no more feed a roman candle duck load to a Fox then I would my Tobin, but, those broken Fox pictures are a little too easy to find on the net. Miller's point is a good one, but, little old me always assumed the weak link might/should be the barrels.
A frame, springing a leak like that, right under 'me little cheapskate nose, would give me the willies. Hell, the picture does.
I'll leave the "hows and whys" to others, and feed my 100 year or so old Tobin, low pressure stuff, only on occasion. The rest of the time, it'll be in the safe.
The guy who color case hardens Sterrit brand tools once told me, "Color case hardening isn't an exact science, and, sometimes, you get what you get".
Indeed.
Best,
Ted
