338, Where are you with your Savage? I don't see any recent posts by you.
I haven't been able to read every word on this thread, so I apologize in advance if I'm repeating something that's already been said or ruled out. I just hoped I might be able to say something helpful here for this situation.
I have a standard, Savage 111 FNS I bought new in 1998, before Accutrigger was even on the menu. Back then their triggers were adjustable, but notoriously inconsistent (some wouldn't adjust below 5-6 lbs). I guess a lucked out with this one and got a good stock trigger that adjusts down to 3 lbs., so I never switched it for an aftermarket trigger. Mine shoots 1/2"-3/4" groups with Federal Bluebox Power-shok 180 gr, when I do my part right.
It won't shoot like that right after cleaning. There's no way to get all the oil out of the barrel no matter how much you swab or run dry patches through. It takes 2-3 shots of burning up oil residues, before it settles down and achieves this level of accuracy.
When I first got it, it wouldn't shoot like this either. I had broken my barrel in meticulously, cleaning to pure white, clean patch between each of the first 20 rounds and cleaned between each 3 rounds for the next 40-50 after that. I had checked my scope mounts. Checked to make sure everything was good and tight. I was still only getting 1 1/2-3+" groups with all kinds of ammo. I had tried everything I knew without taking it to some guru or buying all kinds of aftermarket improvements.
I was pretty frustrated, but what did I expect from a "budget" rifle?
Then one day I was tinkering with it and figured out that both of the action/assembly bolts attaching the stock to the metal were over-torqued at the factory. Even though I'd taken it apart a couple of times, when I'd reassembled, I tightened them back up that tight too. I finally tried simply backing them out and tightening until securely and completely engaged but not "horse-cranked" down into the stock, like it came in the box.
I'm not sure what Savage's proper torque specs are for the action/assembly bolts in your "Long Range" gun, but you might check to make sure yours aren't simply over-torqued. It made a world of difference for accuracy in my Savage, to have these bolts/screws tight enough, but not way too tight.
Hoping your problem gets resolved soon!
