Ruger #1: Scopes and ammunition.
Lots of good replies, and I'd like to post my own experiences. This is my son's rifle. When we got the rifle it had offset rings and a compact variable scope on it. This wasn't a very practical set-up, loading was difficult because the scope was very close to the chamber. It's hard to mount a scope far enough back, so that you don't have to creep up on the scope to get close enough for a good sight picture. Choosing a scope is important, and the choices are somewhat limited. We chose a fixed power because they are usually trimmer than a variable. This leaves the breech a bit more accessible. We also choose rings that were fairly high for the same reason. The last criteria was the length of the scope and the position of the turrets. With the turrets forward, it allowed us to mount the scope towards the rear, for a good "fit".
Testing has been far from extensive, but Federal load 7B is accurate in our rifle. (140 gr Speer Hot-Cor)
A good handload, Lyman #48 as source, is 40.5 gr of Varget, with a F210M primer, in a reformed W-W 6mm Rem case, and a Nosler Solid Base (lead tip, pre plastic) bullet. (recent shortages have us scrounging for brass) 6mm brass is not an ideal candidate for reforming to 7x57, and I don't recommend it. I mention it because these cases are light, 172 gr. and their capacity is larger than some other brands of 7x57 brass. Also, other manuals list 37.5 gr as max with 139 > 140 gr bullets.
The scope in the picture is a PECAR, 2 3/4, selected because it "fits" better than anything else in my scope drawer. The RSI, with it's short barrel, isn't really designed as a long range rifle, nor is the 7x57 an ideal long range cartridge, and 2 3/4 seems to suit our usual hunting situations. Also, lower powered scopes tend to be easier to aim, when shooting offhand, and where we hunt, a rest is a rare luxury.