It just turned out that way. The Shilen I bought was their #5 contour, with a 1.22" dia shank 3" long. I parted the whole shank off, which left the radius transition portion just ahead of the shank. I turned this down to .922", because prior to starting on the bbl job, I'd put the 457 action into a GreTan action fixture, dialed it in, and took a .003" deep cut .924" in diameter to true the receiver face. Of course, I wanted the shoulder of the bbl to set within the trued cut, so I kept it just under that diameter. The new shank turned out to be around 3" long, and made a nice smooth transition into the straight tapered portion of the bbl that ran to .704" at the finished length of 23.5". I had no intentions of re-contouring the full length of the blank, but did put it on a scale to compare its finished weight to that of the OEM American - that's where I came up with the "just over 1/2lb heavier" figure. The rifle is very slightly muzzle heavy now, whereas before, it'd been very nicely balanced. Not a bad trade-off for the improved accuracy IMHO. The groups in the photo aren't anything really spectacular, but the factory bbl was shooting no better than what Travclem is telling us how his Precision Trainer is shooting - maybe worse. Having had the pleasure & privilege of building & owning repeaters built on Stiller, 40X & XB, & V-22 actions, I just couldn't settle for the "splatter" groups out of a rifle that looked as nice as the 457 American. Now I don't have to... I haven't seriously considered replacing the poly pillars with aluminum ones & bedding the bbl'd action in the stock, but it might be a worthwhile project.
UPS delivered another Shilen select match ratchet rifled bbl today - this one is a 28" straight .850" dia blank that's going to replace the factory bbl on my Varmint MTR. Not because that rifle doesn't shoot - it's head & shoulders better than the factory bbl on the American was. But it's not as consistent nor as accurate as the Shilen on the American, and that bugs me no end, so....
ETA - Does anyone have a copy of the file to print these targets? A friend sent the file via email to me several years ago IIRC, but I can't find it, and I'd like to print out a quantity of them for my own use.