So what is the market niche that this cartridge is going to fill?
The last 2 rimfire cartridges that were introduced haven't been very successful, the 17HM2 in 2004 and the 17 WSM in 2012. The manufacturers seem to have overestimated the market demand for both of those cartridges.
The 17HM2 is a great cartridge for shooting squirrels if your rifle will shoot the ammo that is available. The Eley/Remington 17 grain ammo was great, but the CCI/Hornady 17 grain ammo not quite as accurate in any rifle that I've shot it in and the 15.5 grain NTX isn't accurate in any rifle that I've shot it in.
The only 17 WSM rifles that I've owned/shot have been Savage B-Mags and they left a lot to be desired. The ammo cost more than 223, so why bother with the 17 WSM when it cost more and provided a lower level of performance?
