When I had the No. 1's, I know that I "made do" with the factory supplied 4B rings. I also tried the 3B's. I found that Leupold scopes had much longer eye boxes than others. Note, that if you use a variable power, will likely be a difference between lowest and highest power where your eye is "perfect". In the end, I did settle on a straight 4B on front and a 4BO on rear. As mentioned, at times was a M8-4x and other times was an M8-6x36. In the 11 or 12 years that I carried it for deer hunting, I do not recall removing the scope even once, although I did remove the scope at the range every couple years and verify that the iron sights were still "on". For last several years, as I got older and eyes not like they used to be, the iron sights likely became more about "looks" - I would have to be pretty desperate to try to use barrel mounted irons, over a scope, these days. For a few years, I owned a Lipsey's No. 1 in 275 Rigby - that one I could not get my "fat" face down into the comb far enough to comfortably use the iron express sights, at all. That one would have needed carving / relieving into top surface of the comb for those irons for me - was about perfect with the fixed Leupold and 4B+4BO.
Since the iron sights have become less and less a "back up" option for me, I started to remove the sights from the barrel and use what I think are more permanent / rigid mounts. So my Model 70 Win in 338 Win Mag has no barrel sights, and I used Leupold Dual Dovetail bases and rings to mount a M8-6x. Is not actually going to be a simple thing to swap out to a different scope in the field, but I tend not to get so far into back country any more, so I do not bother with Plan B any more.
This is a No. 1 RSI in 30-06 that I had for a while - note how close the objective bell is to the rear sight / rib - I do not think I would be able to get that scope much further back with those 4B and 4BO rings - I do not think Ruger makes/ or made any other height of their offset ring. I never did go hunting with this 30-06, but my 7x57 was set up about perfectly identical, in the end.
This is that 1A in 7x57 with the initial straight rings - can see pretty much can not go further back because rear ring nearly against the turret boss - also not sure if the objective bell would have allowed any more without contacting the quarter rib. You will likely have to "zoom in" to see details of that mounting arrangement. As per this site, I do not know why the picture went sideways - should be a portrait view, but I do not know how to fix that now.
