I have a Winchester Model-70 (ya I know ''who'd have guessed'') chambered in 300wby. I only have less than 100 rounds down the pipe, but for some reason I dont like it. So I looked up J E's post on bolt face diameters shown here; Long actions with a bolt face .Dia of .540 +/- 264 Win Mag, 270 weatherby Mag, 7mm Rem Mag, 7mm Weatherby Mag, 7 STW, 7mm Rem Ultra Mag, 300 H & H, 300 Win Mag, 300 Weatherby Mag, 300 RUM, 303 Brit, 8mm Rem Mag, 338 Win Mag, 340 Weatherby Mag, 338 RUM, 375 H & H, 375 Weatherby, 375 RUM, 416 Rem Mag, 458 Win Mag, and the 458 Lott. Now my questions are; 1. Can I turn my Model-70 into a 338RUM?-same bolt face, and c.o.a.l. of .04 more than the 300wby, or is that .04 longer c.o.a.l. not gonna jive with my action. 2.Would a 338 RUM with a 28'' pipe be near the Edge for velocity? I dont want to monkey with brass necking up a 300RUM into 338 edge. and bother with custom dies etc. 3.Would there be any forseeable problembs, such as needing new bottom metal, will the current action length be ok etc? Im not planning on shooting super long 300gr. Bergers. Probably 225gr, or 250gr Accubonds. 4. I love my Model-70's and unfortunately Winchester does not currently offer a 338RUM chambering, or I could just go that route. Heres my delima I want a 300wsm and I have a 300wby I want a 338RUM and I have 338WIN Am I better off parting ways with both and getting the 300wsm, and wait and hope Winchester/FN comes out with a 338RUM offering sometime in the futre? Or should I sell the 338 and buy a 300wsm, and build my Model-70 300wby into a 338RUM-IF ITS POSSIBLE-?