Nope, I've mounted 6 Mueller scopes on several different rifles, not a problem using Burris Signature Zee rings in mediums most of the time, 4 that I own and 2 that were factory demos. I've used highs a couple times, but that can happen with any scope, not just Muellers. That's one of the complaints we have with NEF/H&R, they need to offer a different hammer configuration so the hammer interference isn't an issue.