I should have stated that my older American SxS's have been "restored" and updated with epoxy bedding in buttstocks/heads. Even so, I deem it wise to avoid any 12 ga. loads heavier than 1-1/8 oz.
Some friends use heavier loads.
JERRY
Jerry,
No need to give up your heavier shot loads. I use the 1 1/4 oz 12 gauge loads listed under RST's Premium Grade as Pheasant loads. They pattern like all get out from my "made in 1894" Remington 1894 D grade damascus SxS. Listed as low pressure just like their other offerings.
http://www.rstshells.com/rst_classic_shotshells_shotshells.htm21