"My Rugers are every bit as accurate as my Remingtons."
Then you are very very lucky. The last M77 I bought shot 6" groups at 100 yards right out of the box. After a months worth of tinkering it shot ok.
I stick with Remington, because I can't spend a month shooting a rifle before I can use it for hunting.
I've never had to tinker any more with a Ruger than I do Remington or Savage in order to get them to shoot. The typical sequence is float the barrel, develop the loads and go. The only problem I've had, in fact, was with my 7mm Rem Mag and 140g TSX. Fixed that with IMR7828SSC.
My buddy and I were out at the range today. He had his Ruger M77 MKII 7mm Rem Mag and I had Remingtons in .308 Win and .30-06. Dave is on a pretty strict budget so for the most part we were shooting we shot 2-shot groups with his rifle and ammo. (We don't expect to to take more than two shots max in the field anyway, so we've always put a premium on the first two shots. In the field Dave has yet to miss, so I guess it works.)
Dave's 7mm RM Ruger, Dave shooting:
0.35", 160g Trophy Bonded, 2-shot group
Dave's 7mm RM Ruger, me shooting:
0.40", 140g Nosler Partition, 2-shot group
My Remington .308 Win, me shooting:
0.70", 168g A-MAX, 3-shot group
My Remington .30-06 Win, me shooting:
0.60", 168g A-MAX, 2-shot group
One thing to bear in mind here is that Dave only has one bolt rifle, the Ruger, and doesn't spend nearly the time or effort in load development that I do. Nevertheless his 7mm RM Ruger has turned in many .5-.6" groups over the years and turned in the tightest groups today.
Here’s a target I shot with my Ruger 7mm Rem Mag. Note that each shot used 0.5g increments of powder, so no two loads were identical. Also note that this was shot in a 40mph crosswind.
Here’s a group shot with my Ruger .257 Roberts. ‘Nuff said.
Or perhaps you would like this one better, my Ruger .300 win Mag from a clean bore (which explains the location of the first shot).
Or my Ruger .30-06.