I decided to take my US/Indian figures out of deep-storage and try TmWwBk rules with them. These forces had not seen action for an AWFUL long time.
The Apaches were eager to make up for lost time as their firing was DEVASTATING and quickly pinned and decimated the US patrol. I was solo-playing the "Its awfully quiet out there..." scenario so the Apaches were able to cut-up two of the three U.S. units (routing one of them) and then melt away to claim victory. They suffered no casualties in a very one-sided affair that compared to some of the historical actions in which fire-armed natives successfully ambushed the US Army (e.g. Nez Pierce, Modoc or Apache wars).
The sole redeeming moment for the U.S. 6th Cavalry was when the survivors of the lead unit, a Lieutenant and trooper, rallied and managed to carry off two of their wounded without being pinned, dispite being under fire from 22 braves, who had hitherto hit everything they aimed at.
I modifed the rules slightly for my game (around pinning/firing to make the both less crippling) but was pleased with the overall rules for small skirmish US/Indian War actions.