I would never headspace off of a cartridge! You have know idea were the resizing die was set. It could be short and some other brand of ammo would not fit. Worse yet it could be long and another brand would have excessive headspace. That is why they make headspace gauges. How do you think it would hold up in court that you didn't use the proper gauges? It wouldn't.
As far as a Remmy trigger going off when the safety is flipped off, that is a piss poor trigger job. Not the trigger's fault.
Also about the nut, if it was the right way to do things or the best way, every gun manufacturer would do it. It's not. Now I am not saying it's wrong but I am sayiing it was the easiest for Savage.
I never said the extractor couldn't be modified, I said it would take a little time.
As far as feeding the Lapua in a Savage, no ones make aftermarket mags for it.
For a Remmy you have Wyatts, SunnyHill, HS, and the AI chassis.
Texas asked which would you do a custom 338 in?
It would be cheaper to do it in a Remmy because of everything I have noted. Would you want to pay $65 an hour to get a smith to make or modify a mag for a Savage or drop in a HS floorplate in a couple of minutes?
It is not that I like Savages or Remmy. Personally I think they all suck and Nesika is the way to go.
But there is a reason why most custom rifles
are built on Remington's.
I am not saying that Savages are total crap- out of the box they are the most accurate rifle. But there is better building blocks for customs than a Savage.