I've recently become interested in the 22TCM round. Go figure a sawed off .223 round with a 39-40gr bullet going 2000fps with little recoil. In my search I see that Rock Island made a conversion barrel , with lighter recoil spring for the G17G3 Glock, but they are no longer being made. Those of you that have tried this how do they work out? Anyone have one that they would like to sell? I see that RI sells a 9mm pistol with a conversion barrel to .22TCM, but I'm not in the market for another pistol, just a way to make a G17G3 chamber a different round. I have a AA .22 conversion kit for G17 and really like it, it is of course a complete slide, and I see that RI offered a slide kit as well, at a steep price. I also have been somewhat checking out the 5.7x28 round, different animal, check out the Keltec P50. Anyway I'm looking for a Rock Island .22TCM conversion barrel, is it worth the effort? what say you?