While I still have awhile to go before I've gotten all of the tattoos (probably need 15 more), the only one that is still locked requires me to get 10 mounted gun kills. I've been stuck on 9/10 for what seems like awhile now. I usually play stealthy, so the mounted gun kills don't come often, but I know I got 5-6 of them during the mission where the guy flies you over to the other island. You must protect the plane and there is a mounted gun right next to the plane. Anyone else experience this? Or, know if there are some missions on the 2nd Island that make use of a mounted gun?