A. Usually a standard dovetail is considered to be a “Weaver- style” mount, which is about 7/8 inch wide, usually with cross-slots. Many .22 rifles have a 3/8-inch dovetail, Airguns, some .22 caliber rifles, and some firearms, have dovetails ranging from 11mm (the most common) to 17mm. 11mm dovetails and 3/8 dovetails although similar in size are different.