Hey...I am building my first AR and was wondering which barrel to get. The gun will mostly be used for plinking/recreational shooting, so probably going to be shooting mostly inexpensive 55gr ammo. Cost is basically the same for both barrels. Both barrels are 5.56 16" Carbine M4 profile... 1.) Stainless Steel 1x9 twist 2.) 4150 Chrome Lined 1x7 twist Which barrel would you recommend and why?