The last two digits of each model are the approximate length of the assembly. RS7519 = .750” journal diameter and 1.9” assembly length. The actual length varies according to what setting you’re using.
The distance from shoulder to gas port varies slightly by barrel manufacturer, but we use .295” from the rear face of the Gas Control body to the center of the gas aperture. The gas port location is probably not the best to use for fitment purposes, though. We have dimensioned drawings under the “Fitment” tab on the Gas Control product page. Thanks for your interest in Riflespeed. If you haven’t used the Configurator on the “Choose Your Gas Control” page at riflespeed.com definitely hit that. That’s the go-to resource for fitment.
@dmk0210