Been searching around on the forum, and the more I learn the more I realize I don't know jack. Two things that appear to be common/popular opinions is that (1) you can't go wrong with BCM, and (2) you can't go wrong with Colt. My budget is $1300 max. Looking at GunBroker, I can find a Colt 6920 or a 6721 in my budget (found some for $1090). These do not have a rail on the fore-grip, which I would prefer but is not critical. I'd probably be plenty happy with one of these and wouldn't have to worry with "building" one. Looking at BCM's website, I can build one on a lower ($350), a standard BCM mid-length upper with carrier and charging handle and OmegaX 9 handguard ($845). I would also need a rear sight ($120+) and mags (3 30rd = $30). This rifle would cost $1350. Back to GunBroker, a Daniel Defense M4 is $1250. Now for the questions. What is the difference between carbine and mid length if the barrel is still 16"? Is the BCM really worth another $250 over the Colt, or are they basically the same and I'm just paying for the tactical handguard? I've seen some AR15's marked as 5.56 and some specifically marked as .223. I've been told that a 5.56 rifle will fire .223 but not vice versa. Is that reason enough to go with the BCM? Are there options with my above BCM build that would help bring the price down but wouldn't give up noticeable quality? THANK YOU Wanna kill these ads? We can help!