Mike, if that gun is marked 12-70 inside a sort of sideways horseshoe or capital C on the flats, then it's original 2 3/4". Quite a few earlier Belgian guns (they'd have 12 over C inside a diamond) were also originally 2 3/4" (typically marked 70MM), especially if imported by someone like A&F or VL&D. If you show a photo of the flats, we can probably make a pretty educated guess as to whether the chambers are original or lengthened.
I shoot a pair of Brit 12's, 6 1/4# with 28" barrels, and they work out fine for me. I shoot mostly 7/8 oz reloads at targets, but usually 1 1/16 oz at pheasants, with some moderate velocity 1 1/8 oz reloads thrown in. They work OK for the few shells I need in a day's pheasant hunt, but I'll stick with those light reloads for targets.
Ted, check out the very light "Helice" sidelock 12 in Cabela's inventory. I think the price is too high for a no name French gun, but talking in terms of "gun for the money", it's likely a better gun than a lot of Brit sidelocks with higher sticker prices.
Last edited by L. Brown; 01/04/09 10:48 AM.