I need a movie name!

I watched a western like movie as a child that i can not remember the name of. It was about a man, possibly an inmate. who created of perfected the repeating rifle. The only real scene i remember is when he showed his creation to the military. But before firing the gun had to be dunked into the horse trough. any suggestions would be appreciated.

Howdy Pard!!

The only scene that I recall, that resembles the one you decribed, is from the film Carbine Williams, with Jimmy Stewart and it isn't a western. It's about the creation of the M1 carbine, while Williams was an inmate in prison for killing a "revenuer" or I.R.S. agent. Carbine Williams was a "moonshiner"

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