You've got ,bull barrels, flat top's, floating barrels, and how many different brands?.......some are gas operated.........

I read that a .223 shouldn't shoot a 556....then I would want a 556 to shoot either??? mil spec?? how long of a barrell. 

whats the best, or rather the most bang for the buck

I know I ask a lot of questions.......any one got one to sell

Thanks to all, (cold here) 22*

John