Any pitfalls to watch for in re-chambering a Ruger #1 from .300 Winchester Magnum to .300 Remington Ultra Magnum (not the short action UM)? The case dimensions appear to be such that the UM reamer should clean up the WM chamber without issue.

Thanks in advance.

No, none at all. Take the barrel off the receiver. Setup, dial in, and ream the chamber, Reassemble and away you go. No extractor modifications needed.

Actully there may be a problem here. The screw holes for the rib of a # 1 are rather deep and of course are over the chamber area of the barrel. If you want to procede with the project I would do some close measuring.
A friend of mine who is a very good gun maker had a project similer to this in the works until I warned him of the problem. After a few measurment it was confirmed that he coulden't do it.

Now he tells me


Actually the hole depth / chamber wall thickness was the first measurement I made after removing the rib. No resulting problems on this one

You mean other than ending up with an otherwise perfectly good No.1 chambered for the 300 RUM?

The no.1 is a fairly light rifle and I don't think I would want that extra sharp recoil for what little practical velocity you get..but guess you done went and done it anyway!

quote:

Originally posted by Atkinson:
The no.1 is a fairly light rifle and I don't think I would want that extra sharp recoil for what little practical velocity you get..but guess you done went and done it anyway!

I hear you on the increased recoil (my thoughts exactly) …and yes I did rechamber the gun. It belongs to a customer (and you know what they say about the cu$tomer).

BTW, I got the gun back a few days ago – this time to install a Limbsaver recoil pad.

Tell him about in stock mercury recoil reducers ,magna port and asprin .

Then you can also get some work on the rebarreling job.....

Glenn