The single-shot Springfield rifle

Is this the western movie I'm thinking about? I think it was Gary Cooper in the lead role.

Towards the end, Gary Cooper and a few Union soldiers are on top of a bluff overlooking the encampment of the bandits. Gary Cooper has several crates of a new model rifle. He opens the crates and hands out the rifles to the few Union soldiers around him. These Springfield rifles are a paradigm shift in firearms technology. The rifles are single-shot utilizing metal bullet cartridges. A soldier can load, fire, and reload the Springfield several times in the typical time it took to load and fire a blackpower, muzzle-loading percussion rifle.

The Union soldiers start shooting down into the bandits' camp. One of the Union soldiers, lying prone and shooting his new Springfield at the bandits, is excited by his new, high-tech rifle and grins at Gary Cooper, "I feel like an Army". Down below, the bandit leader remarks to his colleague that there must be 200 men up on the bluff. In reality there were only something like 15 men.