Gunsmithing M40A3 Scope Mount Holes Spacing Dimensions

[msr_762]

Does any know what the dimensions / spacing distances between hole centers are on the receiver of M40A3's for the scope rail mount? Also, where are those dimensions reference points or datum taken from on the receiver?

Next question. Anybody know what the height offset is between the front and the rear flat bridge area is on the M40A3 receiver's for the scope mount?

Thanks