Smyth Busters: Is It Necessary To Lap Scope Rings?

Steve Ostrem and Caleb Savant, our two roving Brownells Gun Techs who aren't afraid to topple a few Sacred Cows, tackle a question that faces long-range rifle shooters: Should you lap scope rings? The answer is the classic "It depends." In some cases, you can get an excellent fit between the rings and scope without lapping. Other times, you'll have to lap if you want a precise, consistent fit between the scope and rings. Lapping involves removing material from inside the rings so they align perfectly with the scope tube. Correctly lapped rings will make full contact all the way around the tube without exerting uneven pressure on it, which can compromise accuracy. Machined one-piece scope mounts, or well-made two-piece mounts sitting on an in-spec receiver rail, often won't need lapping. If you're saving pennies with an extruded mount, or if you're mounting a pair of rings onto a slightly sketchy base, you may need to lap those rings. So.... NOT A MYTH: Lapping scope rings may be necessary to ensure proper mounting of a scope. How do you figure out if it's necessary? Steve has a tip on how to determine when you need to lap those rings.