Hi Birdhunter50,

I am sorry that I can not give you an exact measurement as I never done it myself but it isn't to much. May I suggest that you speak to one of the Cabella's and ask to see a Merkel as they have them mostly fitted with them. As an old Imperial boy I would say about 1/16" - 3/32" give or take as it is then fastened by way of small screws.

Cheers,

Jeff Gray

.