You'll find the 17 to be the smoothest operating pump ever built. And they seem to have a lot of hand fitting and fitting of internal parts. The rib and barrel are one piece machined from a single blank. The metal is all rust blued. If possible I'd try to add a wood butt extension and keep the original.
Wha??- I have a 1940 Model 12 field grade 28 gauge with a factory solid matted ribbed 28" barrel choked WS-2-- I'd like to have a flat of RST 28 gauge No. 8 shotshells for everytime I have had the same "myth" about the Model 12 solid ribs- it would be a machinist's nightmare to mill out a true cylindrical barrel with rib from a blank of nickel or nickel-chrome-moly steel--the M37 Ithacas and the Model 31 Remingtons and the Model 12's like 3 of mine (including the 28 gauge) all had their solid matted ribs soldered in place in a jig and fixture device--then rust-blued. I used to hunt preserve pheasants with a local peat farmer- who became a millionaire (but never dressed or acted like, say- Donald Trump) He could afford a Boss or a Purdey like I can afford a cup of coffee at McDonald's- yet he shot a 20 gauge M17 Remington with a solid rib and mod. choke for everything that had wings and flew in front of a pointing dog-- You couldn't write him a check big enough to get that M17 out of his big hands either-
