AR2201,

What you have just stated English gun makers knew years ago !!!

No, relly, if you look at any 375 Flanged Magnum double by at least
Holland's and probably others - also ? 369 Purdey ?,
they use / have the reinforced action

That is the easiest way to tell if someone has rebored and not reproofed
a 375 2 1/2" Holland.

500 Nitro