Encore forend mounting hole distance from lug

[GNERGY]

I am cutting down an Encore 300 win. mag barrel and installing a brake for a friend of mine. He wants to put a pistol forearm on it and I need to know the distance from the lug to the center ( approx. ) of the screw hole. I own Contenders but no Encores. The holes in it now are for a rifle forend and are different.
Thanks in advance for the help.
Tarey