Howdy
The cracked frame example may be from me. A bunch of years ago a friend bought a used 38/357 Mag Uberti 1873. (The Taylors rifle is actually made by Uberti) When he got it home he found a hairline crack in the frame. He brought it back to the store and got his money back.
1. All firearms made in Italy are proofed in government run proof houses. The proof rounds used are slightly higher pressure than American proof loads.
2. Proofing only tests the firearm for one proof round. Not the same as firing many, many hot loads over the years.
3. Since my friend bought his rifle used, there was no telling why the frame cracked. Too many 357 Magnum loads? Too many 'extra hot' 357 Magnum loads? No way of telling. But the frame was cracked and he brought it back and got his money back.
4. Frame stretching is pretty much restricted to the brass framed rifles such as the Uberti 1860 Henry and the Uberti Winchester Model 1866 Replica. I have never heard of a steel framed Uberti rifle with a stretched frame.
5. One does not have to restrict oneself to 'Cowboy' loads in these rifles, any SAAMI MAX ammo is fine.
6. That's a very pretty rifle with the checkering on the wrist and fore end.
7. Here is my 44-40 Uberti 1873. I bought it used about 15 years ago or so for Cowboy Action. The varnish is pretty scratched up from being slammed down on various props over the years. Used it for about 5 years until I bought my Henry about 10 years ago. P.S. I have never shot anything but Black Powder through mine (the Henry too) but I would not hesitate to fire SAAMI standard loads through it.