I also have an XVR.
I got it in the spring of this year. Estimate (sorry, I don't actually count each round down the barrel) 800 rds of 45 Colt, 100 rds of .454 Casull, and 600 rds of .460.
Even though it is a ".460", there is no difference in the diameter of the actual bullet. Looking at the Barnes bullets on Midway, they list
Barnes XPB Handgun Bullets 460 S&W (451 Diameter) 275 Grain Hollow Point Lead-Free
Barnes XPB Handgun Bullets 454 Casull (451 Diameter) 250 Grain Hollow Point Lead-Free
I have a scope on mine. My impression was that the .45 Colt was slightly less accurate, but it was the absolute cheapest ammo I could find, so I do not think it was a fair comparison. I shot Hornady .460 (saving all my brass so I can start reloading this winter).
Given the same diameter of the bullets, and what I have observed, I think it is as accurate with any, even thought the point of aim is going to be way different due to the trajectory.
Before hunting season, I got to a full cylinder of .460 in a 6 inch circle at 100 yds from a standing, two hand grip, shooting single action. So I set my max range for hunting at 100 yds. Did not get a shot this season, but figure by next year, I will be ready to extend the range. With the .460, I see no reason it will not work at it's stated range (200 yds) IF THE SHOOTER CAN DO IT.
Also, I think the .460 will really shine with reloading. There are just very few commercial options available.
I absolutely hated the .454 through it, but that may have been the commercial ammo I used. It was very "snappy" recoil - just didn't feel as good to me. Again, reloading would probably solve that problem, but I am currently planning on just reloading the .45 Colt and the .460.
I tried with open sights, but just couldn't do it - 100 yds with open sights is just past where my old eyes want to make it work. 200 yds trying to see a 6 inch circle was impossible for me.