Great fit, drop in and no fitting required.
I had a P220 22 and unfortunately Sig quit making the caliber-x change kits.
I found a P220 slide, it's a carry model slide so .5" shorter, this barrel sticks out .5" which is fine as I'm either having it threaded or having comp cuts machined into it.
Otherwise the pistol functions perfect and didn't have to do any fitting.