I guess I'll jump in here too with my barrel-trying-out-experiences, as I heard mentioned "choked-barrels".
Don't know if all of Ron Smith's (RKS) barrels are choked but at least his stainless-steel, gain-twist ones are, that I've used now on both a 44 1/2 Stevens and a Highwall. I have these on rifles that I use for BPCR Silhouette competition and I am getting some pretty good accuracy with. They are both .40-65s. [I also considered Ron's barrels due to the great results his barrels were getting in Schuetzen matches].
I went with S.S. because Ron mentioned that he was getting some very smooth rifling after using his single-cutter, cut-rifling process, similar, or possibly the same process, as used by Harry Pope (I have never had a leading issue with either barrel. Not even small flakes on a tight patch). I also tried gain-twist for why-nots and also to see for myself if there was any advantage to it. I've heard that Ron's groove-cutting process somehow produces the "choke" rather than producing it by lapping, which I believe cannot be used on a gain-twist barrel.
The barrel on my Stevens 44 1/2, which is 16 twist, set a national record a few years back for 25 Ram target hits in a row. The Highwall, which I built last year and use mostly now, has a 14.5 twist and is doing pretty darn good so far this year. When I first tried it on paper early last year, off the bench at 300 meters with a 20x scope, I shot a very impressive group before the mirage started up and ran the hardest I've seen to date.
Anyway, if you are in the market for a new barrel, an RKS barrel can also be one of your considerations.