Bullets not registering when playing fps games on low ping with wired connection

When playing online games my Call of duty it seems like my packets r travelling at a slow rate or something is blocking the packets because sometimes im clearing hitting the person but my bullets are not hitting them. Im using the cake qos with piece of cake but its not seem to be working because the pronblem is still their. Its weird coz my ping is low like 20 - 40 ping and 0 packet loss so pings not the issue maybe firewall or double NAT my isp is virgin media

... or the other guys are cheating.