I was wondering when someone would figure out how to build an AR rifle in 17HMR. Just looked at Alexander's and was drooling over the prospect of getting one until I saw the price. Maybe I am getting old, but when I can get both a Ruger bolt action and Savage bolt action in .17HMR, both great shooters in their own right, for the same price as one "R-17HMR" I have to think twice.
It's a blowback operated gun which means it will be subject to some of the same issues as a converted 10/22 magnum. It's mentioned in the FAQs that you should clean the chamber every 100-200 rounds. If the AA version can't fire when the round is not fully chambered with the bolt in battery it may do OK. I hope so because a semi-auto in .17 HMR is a lot of fun. However, when it fires out-of-battery due to a dirty chamber the fun comes to a screeching halt. As in destroyed magazine, split stock, and small pieces of brass, wood, & plastic flying around! I clean the chamber of my HMR conversion every 50 rounds now.