I have been working on a AR pistol build for some time now in honor of a family member. Obviously given the time period, I am rounding up parts as much as possible and working in education doesn't leave much money for parts either. However, I have an almost complete upper that I traded for. (Just need a charging handle) My plan was to remove the barrel and replace it with an AR pistol barrel I am trying to buy. So my question is this, I founds this DPMS barrel, http://www.dpmsinc.com/7-KITTY-KAT-BARREL_p_244.html , in stock locally. Would I be able to just simply put this barrel on my current upper and purchase the correct length gas tube or is there more to it I don't know about. Also is this a good price for an AR pistol barrel or should I just wait it out for others. I am also looking to sell or trade my current barrel but do not know how to price it correctly. Thanks for the info and help.