Dwm is right, Norma does list WSM brass, at least 270 and 300 (but not 7mm??).

I won't comment on whether that amount of tape headspace is 'proper' or not, but what I'm reading doesn't make sense to me:

Back up the thread to your measurements, you measured the Federal cartridges to be much shorter to the shoulder than the Winchesters (0.011" shorter un-fired), but you're also saying that the same amount of tape on each cartridge makes the Federals harder to close the bolt on. That doesn't make sense. Did you list and label the measurements correctly? Is any tape hanging over the edge onto the body of the cartridge?

Your pictures reveal that the marks you're seeing in the necks are unquestionably what remains of the crimp. I didn't realize that Win put un-plated primers in their nickel cases. Never seen that before on any Win cases, and never seen any Win component primers that were un-plated. Is that one a reload?

A thing I can tell you is that, IME, WSM brass is _very_ thick and hard (I'm speaking of Win). Many times you'll get hard bolt lift when reloading too light. This seems backwards, but it's how it works and is to do with what stretches first and in what directions when things to bang. I'm not necessarily saying that the Win loads are too light, just hoping to make you aware for if/when you start reloading for this gun.

In any event, good luck getting help out of Savage and/or Winchester/Olin. IMO, it remains in question whether the issue is the rifle or the ammo.