This barrel is made of 4150 CrMoV steel, featuring a chrome-lined bore with honed and hand-lapped rifling. The barrel has a 0.750” gas block that is dimpled for ease of installation and solid lock-up.
I think it is dimpled and these barrels are great 4150 double stress relived they last longer than hammer forged and they’re chrome lining is on par with fn quality more accurate however