If you love the sound of friendly artillery, be sure to crank the volume on your speakers before watching this little gem. Marine Corps Times’ senior video journalist Colin Kelly caught  up with members of Romeo Battery, 5th Battalion, 10th Marines, at Camp Lejeune, N.C., in early February — just a few weeks before the start of their six-month deployment to Okinawa. They were good enough to give him a demo of this wondrous Howitzer, which we — in turn — are happy to share with you. Enjoy. And please be sure to keep these Marines and their families in…