The 50 Gallager Carbine was designed by Mahlon J. Gallager and granted a patented for his design 1860 and was produced by the Richardson and Overman Company of Philadelphia. The Gallager was a breech loaded rifle and used a lever action mechanism to open the breech, whit the lever forming the trigger guard as well. When opened, the barrel tilted downwards to open. This meant that the rifle did not have a fore-end and also no swivels nor had the ability to add a bayonet. The biggest drawback of the Gallager rifle was the fact that it did not have an extractor/ejector mechanism and spent cases had to be extracted manually or with a knife, a difficult feat when on horseback as well as slowing the rate of fire significantly, made the rifle unpopular with troops.

Springfield Armory Museum – Collection Record