I shoot a 6 BR on deer occasionally. I built it on a 788 Remington originally chambered in 22-250. I put it together for my wife but borrow it once in a while. It feeds fine from the original magazines. It's a light #2 Mike Rock barrel 22" 1:8 twist. After seeing the price of a Canjar trigger, I converted the original to be fully adjustable. I have not shot many deer with it, however, the 3 I put down didn't know it was a little BR case that launched the 90 grain Ballistic Tip. I get 3050 fps with a case full of VV N550.
I like to have around 900 f/p of energy on deer and confine this package to shooting over a couple of alfalfa pivots that range out to 350 yards.
This is not a pretty rifle but it shoots any load I've tried into 1/2 moa and many of them into half that.
This is only the 2nd BR that I've built, the other was a short walk around rifle built on a 660 Remington.
This is not my idea of a long range chambering for hunting big game, however, it is a delight to carry and easily handled by those small of frame.
You can stretch the ranges out using the 105 A-Max and a 26" barrel to get 1000 f/p of energy at nearly 500 yards.
I am my favorite rifle builder but I also highly recommend George Gardner at GA Precision. GA's Website