300blk barrel - Jacob Grey Firearms .300 Blackout Threaded AR Barrel

This is a really nice barrel. Worth the money. It’s packaged very nice, and the finish on the barrel is excellent. This is a pistol length gas system just like optics planet says (if you go to Jacob greys website for the same exact product, it says it’s carbine length which is a typo). Mating the barrel to the upper receiver was snug but not hard at all by hand. If you’re like me and plan to use subs and supers you are going to get an adjustable gas block, but keep in mind a hiccup I ran into was that I could not run an aero precision adjustable gas block with a muzzle device. The gas block adjustment would hang over the threads and my muzzle device could not be threaded all the way. A standard mil-spec gas block will work as it will sit flush/before the muzzle threads.

My solution is Kaw Valley’s adjustable gas block. It is still adjustable and will work with a muzzle device. It will also fit under a MidWest industries hand guard, and you will still be able to use the m-lok under it.