Hello BELTFED and welcome aboard.

It certainly is possible to re-chamber a No.1 from 458 to 450 NE 3-1/4". Nice conversion. I have done a few of them, own and use one of them myself.

One thing to watch is the size of the 458 chamber. The last one I had I refused to re-chamber the original barrel. The belt recess was grossly oversize and the 450 reamer would not have cleaned it up by almost 10 thou. The body of the 458 chamber would have only just cleaned up too. The end result probably would have worked OK, but it would have looked shocking, hence the refusal. Had to re-barrel that one.

One other thing, you might need to look at modifying or replacing the safety slide though, when ejecting, those long 3-1/4" shells love to hang up on the standard Ruger safety.

That aside, if your chamber measures up OK, go for it.

Once again, welcome.

Best

ALEX

alexbeer.com