Well, as they say, beauty is in the eye of the beholder.
I'm not planning to sell any of my 6 17 HM2s, 7 17 HMRs, 1 5mm Rem Mag, 38 22 LRs, or 14 22 MRFs, since each fills a niche that I consider worth filling.
I would have to disagree with your contention that the 22 MRF isn't very versatile when compared to the 17 HM2, 17 HMR, and 22 LR. Performance wise, the addition of the 30 grain VMax at 2200 fps is pretty comperable to the 17 HMR out to 150+/- yards, while the common 40 and 45 grain JSP and JHP bullet have been, in my experience, much better game bullets then the lead bullets found in most 22 LR ammo. If anything, the 22 MRFs niche overlaps all of the other 4 RF cartridges to a significant degree. With a better selection of bullets, the 5mm Rem Mag has the potential to be the best of the 5, but the currently available 30 grain Centurian ammo doesn't shoot as well in my Remington 592 as the original 38 grain HP load offered by R-P.
Jeff
