Reflex 264,
I have a Ruger #1 in 450 NE 3 1/4". Mine started life as a 375 H&H mag, I had a Pac-Nor 28" 1-14" twist 3 groove barrel fitted, the same profile as the original barrel. It weighs in a just on 9lbs. I mainly shoot Blackpowder loads (duplex) in it with 510 grain cast bullets, they come out at around 1500 fps. Its quite OK to shoot all day at that. I have fired a few 500 jacketed loads at 2100 fps, then it becomes very lively.
My gunsmith had to open up the loading groove in the action just a bit. I bought a new 45-70 extractor with it and he used it to cut a new extractor groove for the thin rimmed 450 case. The only other thing I had done was to cut a bit away from the top edge of the safety, as empty cases were hitting on it and not fully being ejected, trim it back until its below the level of the loading groove and all is well.
