I'd like to find out the bullet drop for an average 7.62x51 NATO surplus round (Malaysian or Portuguese) fired out of a M1A with a 22" barrel at about 800 feet altitude. I'm planning to ding the steel silhouettes at Red Castle, which start at 200 yards and go out to 500. I've only found ballistics online for a commercial .308 round, which I suspect will have a higher velocity and probably shouldn't be fired out of a M1A anyway. Does anyone have such a chart specific for NATO ammo, or a link to one? Thanks!