Chris, you are the first person that I've ever heard state they are cast, and I would have thought with all the Savage bitchers I'd of heard this one at least a zillion times too, God knows it's all you ever hear about a Ruger.
I'm not sayin you're wrong, just that it's the first time I've heard it, and it's odd it's not mentioned every day.
I'm shocked that you'd suggest someone take it to a smith just to headspace one??? I know you prefer the Rem, but this "is" the advantage to a Savage.
The Savage does not need special guages to headspace unlike the others. Headspace it off a cartridge and tighten the nut, that simple. That's the reason I'd keep the nut "intact" myself. I can buy a threaded and chambered barrel from anyone and install it myself, no lathe and guages required, and I can go shoot in minutes.
I admit, I'm more of a practical person, although I do like a nice lookin rifle, accuracy first though. If Savage had a seious drawback to the barrel nut deal, I wouldn't use it either, I don't think they do tho...
Never having paid a whole lot of attention to the Savage extractor of mine, I pulled it apart to see what needs to be done to open it up. It would take me about 30 minutes to do a great job modifying a Savage extractor for the Lapua case, simple as that. I think Sierra could have done it themselves.
For about $15 in parts, I could modify a Magnum bolthead and extractor, sell it for $50 and make a good profit.
I could modify a $2.87 extractor and sell it for $30 too.
Let your smith open your bolt face and slide it in.
Shouldn't be a problen getting it to feed the Lapua, if you wanted it to.