Lever Gun Series: 1873 Trapdoor Vs 1860 Spencer

The 1860 Spencer repeater was adopted by the cavalry but then mostly abandoned for the single shot 1873 Trapdoor rifle & carbine.
That seems like a curious move, so in preparation for more of our future Lever Gun Series videos, we decided to see if we could figure out why by testing both rifles against each other on the clock.
Was the US Military right at the time, or not?
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