It's long gone now, but just FYI...
Excel Arms did offer a 17hmr version of their Accelerator pistol. Once, maybe 10 - 15+ years ago? Maybe longer.... This was when the model just came out, and it was available in 17hmr, 22lr and 22mag (17hm2 wasn't around yet).
With the first guns that shipped, the 17HMR versions had lots of problems with case heads rupturing, and the 22 guns,,,, didn't. As a fix, Excel offered to convert returned pistols to 22/whichever, which pretty much everybody did, just to get a working gun.
I was watching all this at the time because I really wanted the 17hmr (I already had the S&W 647) but the Accelerator was a new design, so I waited 3-4 months for other opinions,,, and by that time they weren't offering it anymore.
They still sell the same pistol but only in 22mag and 5.7 --
http://www.excelarms.com/handguns/acceleratorpistol.html ...So it is
not impossible that you
might chance upon an un-converted 17hmr Accellerator, used. It prolly aint gonna work right tho.
I recall that a number of companies back then tried to convert their existing 22mag rifles to 17hmr, and gave up because it wasn't an easy modification. I specifically remember that Ruger tried for a while to convert their 22mag rifle, and eventually admitted that there wasn't going to be a 17hmr version at all.
Volquartsen was the
only company back then that made a 17hmr semiauto rifle that people said really worked correctly. It cost $$$$, but it worked and shot perfect.
I don't recall any other companies that made an autopistol in 22mag, that would have been suitable to even attempt converting to 17hmr. There was that goofy longslide pistol that came in 30 carbine and 22mag, but that was some years before.
...And I'm re-registering and posting on this dead topic now, because it's years later, and I'm coming back looking for a 17hmr pistol.... and there still aint any. :>\