User blog comment:Didikins/My favorite things in Black Ops/@comment-24087008-20151027011250/@comment-24756040-20151105022052

The Stoner kicks a lot more than the HK-21 does, but has 200 more centerspeed than the HK-21. The Stoner kicks a lot and recenters quickly. It has the same horizontal recoil as the Uzi, if I'm not mistaken.

In my opinion, logic would say the HK-21 has more manageable recoil due to the lower kick values overall and a lower fire rate.