Are they out there? If so, where? Thanks!

Thin

That company who made the Carbon 15 before boshmaster bought them used to make a .17 hmr upper I think.  At least I thought they advertised one for a while.

If you're interested, there's some info on converting the Ruger 10/22 magnum to .17 HMR here:  [url]http://www.artifex.ws/hummer.html[/url]

Oly Arms, SSK, & others will make you a complete Upper in .17Rem

I have never purchased a complete .17 Rem upper from them but have bought .17 Rem barrels in stainless steel from Olympic Arms.  A really simple conversion.  Uses the standard .223 bolt since the case head of the .17 is exactly the same diameter as the .223 and the .17 Rem cartridge feeds just fine from standard AR mags.  Very, very accurate and almost no recoil, but lots of energy when you push a 25 gr moly-coated bullet at nearly 4200fps.  You'll love it.

Thanks for the replies. I think I just started a new project. Damn, another AR. Life is good! [:D]

might also check tromix and kurtz kustom (s) in the industry forum
RR