First, these are wonderful forums. Second, my first post - a question: would a Pre-fit Pachmayr Decellerator pad for the Ruger 77 MKII fit, or likely fit, a Ruger #1 (.375H&H)? Thanks.

Yes, it will fit right out of the box but it will look like crap. Either way, it will need some sanding to get it to fit your rifle perfectly.

I tried the pre-fit thein from Pachmyr for my Rem700ADL and Rem 11-87. Neither pad fit both were too small so ended up trading for large Pachmyr pad and doing new pads the standard method. I do not recommend pre-fits.

From measuring the butt of several No.1's, and looking at the chart for the prefit Pachmayr, it looks to me like the one made for the Fwt. M70 (wood stock) comes closest to being the same size as the Ruger No.1's. They are not the same size as for the Ruger M77....

I put a pad on my Ruger #1 45/70. The fit was very good , but not perfect.