As far as I'm aware, Ruger didn't chamber the .404 Jeff in their M77RSM (Deluxe Magnum) rifles.

Ruger did, however, do a limited run of 404s in their No. 1 single shots.

But apparently the barrels (or some barrels of this run) were not of the correct diameter for the .404 slug (.423, I believe), so buyers who were primarily shooters and not collectors were not happy to say the least.

I own another "limited-run" No.1, a 300 H&H built on the 26" 1-S medium sporter, and it's a very accurate shooter.

It's too bad, really. I've wanted a .404 Jeff, and would happily take one in a single shot or Magnum rifle if Ruger produced them again.

CZ does make a "high-end" Safari 550 in .404 Jeff but the on-line reports have been so negative (like those posted over on Accurate Reloading) that I've decided to hold off for now.

Hope this helps.