Dennis does good work from what I've seen.
One other thing to consider when getting a center fire converted to rimfire is the chamber area of the original barrel. If you are planning on trying to keep the rifle looking original by retaining the barrel then you will need a custom liner. The liners that used to be available here were made to reline rifles that were already chambered in 22rf. Many moons back, I put a "sleeve" into a Remington Rolling Block that had been through a fire. I got the barreled action for $25 and it needed a lot of TLC just to get it working again. In the end, I wanted to keep it looking original as all of the parts I needed were available from Numrich. All except the barrel liner of course.
I ended up purchasing a Green River barrel blank turned to 1 inch diameter, through bitsofpieces.com with a 224 diameter bore with a 1x12 twist rate. This was an excellent barrel considering the price. The biggest issue was to get one in that was long enough to fit from the chamber face to the muzzle. It took them a couple of months to put it together but Barry prevailed.
OK, the existing barrel had to be completely drilled through with enough left to retain the original appearance and markings. The rifle had been chambered in 43 Egyptian. It worked out quite well actually.
First the barrel was cleaned up with a 7/16" drill that had a 3/8" piece of drill rod welded to the shank. NO, I didn't make up a pilot for the drill. The long original barrel made it impossible to chuck up so it had to be drilled out by hand. This isn't as big a deal as it sounds. The bit was only slightly larger than the original bore.
Next, the chamber needed to be cleaned up. To make life easier The chamber area was cleaned out to a straight profile with a 5/8" bit.
Next, the barrel was profiled on the lathe, using a steady rest and half rest. Not a lot to play with here as far as overall length goes. The GR barrel was just 30in long. In hindsight, if I were to do this again with the same chamber, I would have picked up a hammer forged barrel from Wolf in Texas with very close diameters where I needed them.
To shorten this up, I had a 30 in barrel liner with a 7/16" barrel and a 5/8" step on the chamber area.
This rifle was going to be made up as a 22WMR and I chambered it before installing it in the existing barrel, which was still in the receiver. That was a mistake in hindsight as well but WTH. The mistake was not taking the barrel out of the receiver.
OK, now the install. When I first decided to attempt this build I was going to solder the sleeve into the barrel. That can be an awkward and tedious job with all sorts of pitfalls. In the end, the tolerances between the ID of the barrel and the OD of the sleeve were within .003-.005 in all the way through. Solder would have worked but I was worried about voids. Not really a biggie, considering the diameter of the sleeve. I opted for Titanium Putty instead. This was a blessing in disguise. No heat or warpage created by heat. I cleaned up all the surfaces first with wood alcohol, then applied a liberal coating of TP to all the surfaces I wanted bonded. The "sleeve" slipped all the way in to the inner shoulder and stopped a hair to far in. A quick tap on the muzzle brought it back to flush and helped set the putty. This stuff sets up pretty quickly and has very good tensile strength for jobs such as this. I also use it when making up non restricted 30 M1 carbine barrels and when making up new barrels on prohib pistols to get them reclassified. Great stuff. Not cheap but it sure does the job.
The next step was to clean up and crown the excess sleeve sticking out the muzzle end. The chamber area was, luckily, perfect.
After this, making up an off center firing pin and cleaning up the breech block for a quick test fire. It worked. Then came a couple of months fitting the parts, cleaning up the metal, bluing etc. That rifle was a lot of work and in the end, far more expensive than purchasing a new rifle. It was very accurate but in the end to heavy to lug into the field. It now resides somewhere in south Manitoba where it was scoped and set up for long range Rabbit shooting.