The 22lr, 22 Mag and 17m2 Are allowed to be loaded to SAAMI 24,000 PSI MAP (Maximum Average Pressure) and are commonly loaded to 22,500 PSI
The SAAMI MAP for the 17HMR is 26,000 and it is commonly loaded to 24,500. So you can see that the 17HMR is only SLIGHLY hotter than the other rimfire rounds. I certainly don't believe that the slight difference is beyond what the Favorite will handle and I am almost certain that it is now being chambered in the 17HMR so if you want one either build it or buy it. You will be alright.
By the way those pressures are from CCI's tech people and they are measured with the newer piezoelectric strain gage method rather that the older and not as accurate Copper Crusher method in which pressure was given in C.U.P. or Copper Units of Pressure. I have always wanted a Favorite and one of these dyas I just may get one.
I have been hoping that Varner would finally get their act together and produce their beautiful version of one.