I haveownedseveral Model 12's in the past, and IMO it is the finest pump shotgun ever made.

Me too .

I would avoid heavy steel loads of large shot . I have a BPS w/ a steel special bbl that has a 4" score at the choke from BB at 1350 and 1 1/4 oz, with that saidupto 3's would be ok in 1oz loads . I have a Boito o/u with thin bbls that has up wards of 5-600 rounds thru each bbl of 1's and 3's up to an ounce and 1450 and had no problems(read $200 1978-82 Brazilian cheapo).

My Dad shot some slugs in his 30" full choked50's vintage Mod.12 with 50ydgroups of 4" 4" low with the bead on the reciever "groove"