Does anyone know the proper thread size, etc. for the Lyman 66 aperture sight? I want to get a smaller aperture for mine, but am not having much luck.... I've seen on the Lyman site that they list two... a hunting and a target.. but one is shown to be 1/2" and the other is 5/8"... I'm assuming they are talking about the overall diameter of the aperture body itself, and not the threaded part... and of course not the aperture opening... any ideas?

Midwayusa.com They have williams that are supposed to fit the lymans. They list the different aperature hole sizes.

Williams will fit? GREAT.... that simplifies things quite a bit.... I appreciate it...