Complex sentence: Hardin found that his own weapon, a worn-out cap-and-ball pistol with a loose cylinder, would not fire; he dismounted and managed to discharge the gun by steadying the cylinder with one hand and pulling the trigger with the other.
Split into simpler sentences: Hardin found that his own weapon, a worn out cap-and-ball pistol with a loose cylinder that would not fire. He dismounted and managed to discharge the gun by steadying the cylinder with one hand and pulling the trigger with the other.