I've always used Foster-style slugs in my 1980-vintage 12-gauge Ithaca M-37 and had excellent accuracy out of them. The LE agency I work for limits us to Fosters, so I've never used anything but Fosters. I was in the gunshop today and thought I'd pick up a couple boxes of Rottweil-Brenneke "Classic" 1-1/8 ounce slugs to try, just for fun though.
The shop owner suggested that shooting Brenneke's in my M-37 might not be such a good idea since Ithaca's slug-bore (inside diameter) is tighter than the slug-bores on other manufacturers' shotguns. I suppose it could be so, since when I calipered the M-37's bore at the muzzle years ago, it miked .705-inch. I didn't give it another thought, since I figgered that my rifle-sighted "Deerslayer" model would naturally be bored a bit tighter.
Anyway...the gunshop owner said that the antimony-hardened Brenneke slugs wouldn't swage down as they travel through the barrel as easily as the softer lead Foster slugs, and this would accelerate wear on the M-37's bore. Has anyone here ever heard of that being a problem with a M-37 Ithaca slug gun?
Brenneke slugs have been around since what...1895? And the Ithaca M-37 has been here since 1937...right? I'd have thought that if Brenneke slugs weren't compatible with an Ithaca slug gun, that issue would have been dealt with somehow a long time ago, but maybe I'm wrong. Appreciate any advice.