Curious about the behavior of the Ruger M77 mount - no experience with it, only fiddled with scoped rifles prior - do they inevitably get marred from regular use? The way the rings are designed, it appears as though a lot of clamping pressure is placed on a very small surface area, more so with the Leupold rings.
That is something I hope to find out soon when I get a chance to shoot it toward the end of this month.
I have higher hopes for the Warne M77's as opposed to the Ruger rings or the Weigand mount. The reason being, they apply full surface clamping to both frame cuts and full contact in the top cuts. The Ruger rings offer full surface mating on the top, but only on the screw side of the side cuts. The opposite side shown here, only grips a small part of the very top of the side frame cut, and that isn't enough for the jarring recoil of heavy loads.
I could never keep those rings tight, even using red Loctite thread locker. Loads pushing a 325 gr cast bullet to 1450 fps, or a 300 gr XTP to 1650 fps, jarred the rings enough to mar the steel of the frame on the side cutouts and loosened up within a few cylinder loads.
The Weigand mount offers the full surface mating to the side frame mount slots (and an anchor in the rear sight base), but uses spring pins to anchor into the top frame slots. The problem there is those spring pins offer only very small surface area contact. I shot about 6 cylinders worth, removed the mount, and found the pins were driving up divots in the top strap.
For those familiar with the SRH, the steel of the frame is not as hard as you would think on a revolver containing that much pressure, actually moderately hard. This pic shows the spring pins of the Wiegand mount beginning to flatten, and the bright areas where anodizing is missing is from friction with the divot of metal being driven up on the frame.
This is the Weigand after mounting, but before I took it to the range.
So the Warne M77 mount separates into halves, offers full mating contact to both sides of the frame cuts, as well as full contact with the top strap cuts, basically exactly what I was looking for. I expect this will be as good as it gets, and if they fail too, I'll have to back down my loads enough so the recoil torque isn't as violent.
So far, the scope tube is holding up fine through all previous testing, with only moderate evidence of anodizing coming off at the ring pressure points. Looks like the Bushell Elite is no longer in production, but I bought it because it was rated waterproof, fogproof, nitrogen purged and capable of handling .454 recoil. It's doing a whole lot better than the mounts I've tried so far.