The 7 MS have 20" barrels and the 2 barrels that I have had were slightly larger, maybe longer, in contour at the shanks when compared to the factory 18.5" and 20" barrels. The difference wasn't much, easily addressed with a little sanding, but any difference, no matter how small, is a difference.
I have dropped 2 7 SS barreled actions, 223 and 260, into 7 MS laminated stocks without having to modify the stocks in any way for fit.
