I liked Bob Milek's writings. A name I haven't heard in quite a while.

Looks like a Rem. XP100 with a beside-the-bolt, Sako guide and extractor.

I've never owned one, but I've shot them a few times, once on the way up to Babine lake to check boat licenses. LOL - I rested the handgun on the bow of the "police" boat and shot a big crow out of a Spruce or Fir tree about 200yards off. The XP in .221 Fireball worked perfectly - that one liked 52gr. Sierras.
My late, close friend Sandy also had one that was having problems. Once I got him to back off his loads a bit, it worked a lot better, no more blown primers.LOL He also had a little 4X scope on it and usually put a 1 1/2" disk of 2" thick mild steel on a swinger, out on the 50 meters line. Didn't take many sessions to get it really pocked up on the surface. That was quite a simple target, actually, standing freehand or sitting with a rest. That particular one liked 40gr. Vmaxs at close to 3,000fps iirc.
I really have no use for a bolt actioned handgun as we can only shoot handguns at approved ranges & if I'm going to shoot handguns, might as well be something I like, as with my wheel guns.
I would like a .500 S&W with a 5" ported bl. That was fun.