04-19-2012, 11:22 PM
These are the picitany rail dimensions. In my work I have measured many different rails on guns and have found a lot of variation in the dimensions. The clamping systems for most mounts allow for this variation so I wouldn't get too hung up on the exact dimensions shown on the spec's. I have always used the layout dimensions at nominal for my cad layouts and design with no issues.
Collecting tools for 30 years.