Can You Believe It - .50 BMG Rated?!

We received a Facebook message from Grant H., one of our customers asking if our Keystone Rings were .50 BMG rated. He had another brand's rings that were .50 BMG rated and he had issues with them. We responded saying we had not tested them on a .50 before, surprisingly, no one here has a .50 BMG rifle with a spare handful of rounds ready to go. Being the curious folks that we are (George even has the shirt to prove it), we sent a set his way for some testing. The only thing we asked for in return was an honest review. That is what we received, we only redacted the original company's name since we didn't want to speak negatively of another company's product. The following is his account:

I received this set of EGW Keystone rings following the failure of a set of redacted rings that I purchased along with a SHV 4 scope; both of which are advertised as “50 BMG rated”.

I have had no issues with the optic but had significant issues with the rings, as after putting maybe 70-80 rounds through the gun after mounting, I noticed something shiny at the bottom of the ring, only to realize that the ring had cracked at the base (see below). I spent probably 50 rounds of load development wondering why ammo I had shot in the past was now not shooting all that well.

I took the rings off and began looking for another set that was not too expensive. (I should note that I never heard back from redacted regarding the rings) I ordered them through amazon, and they were willing to take them back for whatever reason, though it was long past their return window.

I stumbled across the Keystone Rings on Ebay and decided to reach out to EGW to see if they were rated for 50 BMG as it was not on the website. Turns out, the answer was basically we don’t know but we’ll send you a set to see if they hold up.

Upon initial inspection, the rings seemed to be sturdy. I mounted them up with the initial recommendation of 65 in-lb on the crossbolt and 15 on the top screws and took it out to shoot. This scope-ring combo was the slickest I have yet to mount. The scope would freely rotate in the bottom half of the rings under its own weight and likewise with the gun sitting on the bipod would slide back until it hit the bell. After about 10 rounds, the scope had slipped about 1cm which did not surprise me, considering how slick they were in the rings.

Looking for some solutions, a few recommended I bed the rings, which I must admit, I didn’t know was even done. I have bedded actions, only heard of rings recently. Looked up the process and it seemed cheaper and simpler than buying a lapping kit for one use. This weekend, following the bedding, took it out again and I think that solved my problems.

The scope didn’t freely rotate in the rings, no easy slippage during mounting, and it held up just fine to about 20 rounds of cheap M33. Groups were smaller than they have been in a while, so I guess that means I can start trying to find a load again.

Thanks again to EGW for the set of Keystone Rings, I certainly wouldn’t hesitate to buy another, especially for rifles that do not punish optics and mounting systems like 50 BMG does. They held up just fine, with this scope, they needed a little extra work.

We had some further correspondence with Grant after he sent this review and he commented further on bedding the rings saying:

"The scope seems significantly more slick than most that I have mounted; granted I've never had anything that necessitated lapping. It is a 50 though so I guess it's part of the challenges faced with them. Scope weight is also probably a big issue. I decided to bed the rings and that fixed all of the slippage issues, which I think were more of an issue with the scope than the rings themselves."

When Grant came to us about the scope slipping, we recommended a slightly higher torque setting and putting a piece of paper between the rings and the scope. We have infrequently seen slippage like this occur before and have found a small piece of paper allows for just enough traction for the scope on the slick rings.

Our Keystone Rings can be purchased on our site, we also offer Practical and Tactical rings. More information about our rings is available here.