fw -
I have installed several barrel liners, a couple of .22 calibers in Stevens Favorite single shots and one .45 caliber in an old swamped hand forged Kentucky rifle barrel, but its been a long time ago.
On the .22s, I ground the drill with a swept back point angle, and it followed the bore just like a piloted drill would. On the .45, I got too smart for my own good, and tried to "aim" the drill by clamping the barrel in the tool post on a lathe, with the drill in the headstock. This didn't work as well, and the drill drifted off center at the muzzle. I had to recontour the barrel to get the hole centered at the muzzle - lots of grinding involved.
In all three guns, I glued the liners in place with Acraglas. I wouldn't recommend soldering unless you have a burner or forge capable of heating the entire barrel, end to end. I didn't, thus the Acraglas. None of the rifles were tackdrivers, but they were reliable shooters, certainly better than before the liners were installed, and I was able to put three nice rifles back in circulation.
Bill