Blood on the RisersBy: John Leppelman In three straight years he was a paratropper, and army seaman, and a LRRPand he lived to tell about it. As an FNG paratrooper in the 173d Airborne, John Leppelman made that unit's only combat jump in Vietnam. Then he spent months in fruitless search of the enemy, watching as his buddies died because of poor leadership and lousy weapons. Often it seemed the only way out of the carnage in the Central highlands was in a body bag. But