I am looking to build a long range and accurate ar15 that can shoot both the .223/5.56 ammo. I already own a Bushmaster 7.62x39 AR that has the power for shorter range shooting, but now im ready for the standard AR15 caliber. I have been searching around for the past month and i am going back in forth between the White Oak Arms 26" SS Match Barrel Upper in a 1.8 twist with Wylde chamber or Rock River Arms upper 24" SS Varment Bull Barrel A4 reciever w/ 1.8 twist. Jon from WOA is out of town all month so i can't really ask them any questions about this upper as like what receiver that it comes with or anything of that nature. Im a decent shooter, still learning so i could really use some expert advice between these two uppers. I will be mostly using this gun on a bench. Ive been going back and forth for weeks now trying to decide.