First off, don't be surprised with the accuracy you get while working up loads. The 6BR is a born bug hole maker.
Varget is/was the go to powder for the 6BR. Got it but don't care for cutting kernels in my powder measure so it's not my first choice and besides, it stinks when fired.
Don't let my opinions keep you from trying it. My shooting buddy loves it and he's hard to beat when it comes to group shooting.
I'am a BIG fan of Accurate Arms powder. AA2230 and AA2460 are my go to powders. I use them in everything I shoot from the 20 VT, on up to 30.06 and everything in between.
60 grain Bergers with 29.0 to 30.0 grains of AA2230 will get you bug hole accuracy. YMMV so work up slow.
I'am not a "speed freak" when it comes to building loads. I like mid range loads with a little wiggle room so if there's a temperature shift from where I load to shooting times, I don't run into pressure problems.
Heavier bullets? Back off a bit and work up till you get your accuracy node.
I shoulder bump and neck size with Forster Bushing Dies. Throw in a body size if the bolt starts getting hard to close. My brass doesn't grow and I'am getting 25 to 30 reloads with no problems. Load "into" the lands if the throat is short enough. You can always back off from there.
You're working with a Savage so if you don't like that caliber, spin on another caliber barrel, swap bolt heads and try something else.
I single feed so no problems with mag length.
Both of my Shilen and Pac Nor 8 twist straight pipes are bug hole makers without too much work.
Next thing, you'll be necking down the 6BR to 22BR or even to 20BR. You'll be hooked!
HTH, Mike.