Aces Wild by E Jefferson Clay
They were an odd pair, the one-time Union captain and the former Confederate sergeant. They'd fought each other during the Battle of Pea Ridge and then ended up fighting shoulder to shoulder when a common enemy showed his face. Bo Rangle, leader of the guerilla force known as Rangle's Raiders, took advantage of the slaughter to steal what the two opposing forces had been fighting for - two hundred thousand dollars' worth of Confederate gold. Hank Brazos and Duke Benedict never forgot that day, or each other. And when, by chance, their trails crossed again after the War, they decided to team up, find Rangle and reclaim that gold for themselves. And while they were at it, they swore to get revenge for all of their comrades who'd died that day back in 1862