Tube Size

Contrary to what some people say, tube size is important, at least as far as riflescopes are concerned.

Tube size is the diameter of the main body of the rifle scope, and it's a very important measurement. The American standard is a 1 - inch tube; the European standard is a 30mm tube. You need to know which your scope is, so that you can purchase the correct ring size to mount it to your rifle.