AR15 Uppers from Oly Arms, Ok out of box?

[Lawfficer]

I just bought an AR15 upper in 300/221 a/k/a 300 Whisper to mount on my Colt 6920 from Olympic Arms. I was wondering what everyone's expirance is with this gun and if it shoots ok out of the box. I have seen where and adjustable gas block is needed to get it to cycle properly.

Right now, all I have is 165gr round to shoot out of it, most of which will be supersonic. I seen no point in loading sub-sonic rounds as I don't have the can for it, yet.


Thanks!