W/the longer chamber length of the X-Frame I suppose one could load up some 454's w/a longer C0L. I fired 454 ammo in my 460 as well as 45 LC and maybe someone will try 45 auto rimmed someday. My experience w/other cartridges in the XVR was that it sounded puny ~ yes, on the heels of the 460 everything sounds/recoils anemic. However, thru my muffs, sounded like squib load just begging to happen.
The XVR is much different than shooting 38Spl/357Mag, 44Spl/44Mag, 45LC/454Casull. It has about 0.5" additional chamber that in rifle terms would be call freebore and the resulting pressures much lower. I know in my case some would have heavier recoil/bark and another would be quiet, like not a full burn. Anyway ~ will only shoot 460 in my X-Frame from now on. Will shoot 45LC occasionlly in my FA83 ~ maybe one can work up some load using those racy looking 200gr Barnes for the 460 rnd in 45LC case and still function in the standard 454 chamber?