I built lots of custom guns on Bighorn, Mausingfield, Borden, Badger Ordinance in manners, mcmillan and chassis ... etc. They are all great. They all shoot great; however, the AI rifles are better overall - they shoot and they just work rain or shine - you never get surprised. If the ergos of the AI chassis speak to you then that's the way to go. If not, then there have been a lot of good recommendations in the previous posts.