I've built a 450 NE on a J.P.Sauer scalloped boxlock ejector 16ga. I've a friend building a rifle on the Sterlingworth. He's balking at the lockup, noting that the actual locking surface is tiny. The Sauer has double underbite, crossbolt, and heavy sideclips. I've fired 200+ nitro loads thru the Sauer with no problems. Also, the 16 ga frame is perfect for a 450, where the Fox is pretty chunky. My Sauer weighs 10 1/2 lb with mercury recoil reducer in the butt and balances just forward of the hinge pin. There's a ton of work involved here and starting with a proper action is a decision you won't regret! I bought my Sauer from an on-line auction with bores ravaged by pitting. The action was perfect, the engraving superb, and the wood, though broken behind the action, was repairable with incredible figure. I think the Fox may be marginal regarding action strength and desirability when finished. Just the opinion of a guy who's done one!