Update on the Ruger #3 Rebarreling:
The modified reamer came back from Clymer at no charge. Thank you Todd @ Clymer Tool. I cut the barrel thread 1-16 and rough tapered the barrel on my lathe. All barrel work was done between centers with a steady rest. I chambered the barrel to 357 mag allowing for zero headspace. The block rubs the back of the case just before coming fully into battery. Afterwards I ran the 357 max reamer, getting the degree of throat, as the max reamer has a long gentle throat. I finished this up by hand, so I didn't over do it.
I ran up the barrel in the receiver tight, and drilled and tapped the scope blocks, so i had an orientation point for cutting the extractor groove. I put blue Dykem on the breech of the barrel and traced out the extractor outline with a scribe. I made the cuts using a 5/8 X 1/8 keyway cutter. It turned out the Hornet extractor was too long and protruded into the chamber, making loading of the dummy test rounds impossible. The rim of the Hornet is .350, while the rim of the 357 is .440. I used a 7/16” end mill, which is .4375 diameter, to trim back the ejector, getting it to the proper radius at the same time. After a little chamfering and deburring, it was good,
I made a graph on paper of the factory Ruger barrel dimensions, measuring every inch. I wanted a .725 diameter at the muzzle of the 24” barrel, so I adjusted the barrel dimensions accordingly, to come to this figure. Using the lathe, I cut steps every inch on the barrel, allowing a few thousandths extra for final finishing.
Here's the peculiar thing. I was planning to use a mill file on my lathe to blend in the steps on the barrel, as I was not at a constant taper. By chance, I had spoken to a gunsmith, who has built many custom rifles, who said I should make an adaptor to turn the barrel on my wood lathe. He said I should use a 7 inch angle grinder, with a flexible sanding pad at about 60 grit. The reasons I was given were, the wood lathe runs twice as fast as a metal lathe, giving a smoother cut, and you don't want the abrasive particles getting in the carriage, cross slide or on the ways of the good metal lathe. This worked better than I could have ever imagined. The steps were gone in no time, and I soon switched to 80 grit 1” shop roll, then to 320 grit, and finishing up with some crocus cloth. I have a 6" buffing wheel I followed up with, before giving a quick cold blue to ward off any rusting.
This morning I went to the range to try out my project, after mounting a spare Bushnell 4X scope. I only had two types of ammo loaded at the present. 38 spcl @ 3.7 gr Bullseye w/ Saeco 382 swc @ 162 gr, sized to .358, cast of wheel weights, along with some 357 mag @ 15.5 gr 296, using the same bullet. The 38 spcl at 50 yards, was grouping 5 shots under an inch, while the 357 mag grouping was around 2 inches at the same distance, and POI was about 3 inches higher. The 357 mag accuracy doesn't proove much, as I have many molds for this caliber. Quite possible one of my gas check molds might proove better. I shot 75 rounds, with no leading whatsoever. I have a Hicks accurizer on the #3, and didn't even have it contacting the barrel. There might be some potential here also.
One of the next issues is whether to cut the end of the forend, getting rid of that awful barrel band groove.
Overall I am quite pleased with the results of this project, which was my first attempt at a rebarreling job.