engineer_comp_geek:
One clear example that I am familiar with (because I live close to there) is the battle of Gettysburg, A smaller number of Union troops held off a larger Confederate force on the first day the battle due in large part to the fact that the Union force consisted of a lot of cavalry men armed with repeating rifles. This made the Confederates think that they were fighting a much larger force than they actually were and made them a bit more hesitant to charge their lines.
Once the battle really kicked into high gear though it was mostly rifle-muskets against rifle-muskets (for the infantry guys at least). Repeating rifles just cost too much to make and there weren’t that many of them on the battlefield. While the repeating rifles didn’t have much of an effect on the all out slug fest that followed, they did allow the Union troops to hold off the Confederate advance long enough for Union reinforcements to arrive. The entire battle would have been significantly different if the Confederate forces had been able to completely overrun the Union forces on that first day.
History itself might be really different. The failure of Lee and Co to take Little Roundtop and Big Roundtop turned what would have been a defensive battle for the Confederates into a an offensive one. It was a battle they could have won if that were to happen. Of course we are into speculative history here so I will hijack no further
Capt