This is a very rare example of one of only 52 Model 1882 experimental short rifles manufactured for trials in the 197000-199000 serial range. The intent of this series was to develop a single rifle configuration that could be adopted by both the Infantry and the Cavalry. It had merit in 1882 and has the same merit in the U.S. Military today. The idea was to save manufacturing and logistics cost by using only one configuration. Additionally these rifles incorporated some requested improvements at the time, such as a shorter barrel for better handling, different rifling configurations for improved accuracy, cleaning, and improved rear sight modifications. The 52 examples of these rifles were manufactured for test trials with the most unique features including the 28 inch barrel, and a special friction fit breech block with a mechanism that enables it to be retained at any position between fully opened and closed; a feature only found on the Model 1882. Of the 52 made, known examples have wraparound front and rear sling swivels to facilitate easy entry into a cavalry rifle scabbard, half were manufactured with the traditional, 3-groove rifling with the other half manufactured with a new 6-groove rifling system; of these, half were to be equipped with the new experimental triangular sliding bayonet with the other half equipped with a blade front sight with lug for socket bayonet mounting. This example has 3-groove rifling and the lug front sight. These are a very rare rifle with only a handful extant today, as very few actually survived the tests with almost all being cannibalized or destroyed after the testing was completed. Thicker/heavier barrel than standard with a larger outside diameter (approximately .780) fitted with the experimental M1882 rear sight with locking screw in the center of the windage slide, with the leaf marked "28 B" on the upper end and "28/B" on the left of the base. Low arch friction fit breechblock marked "U.S./MODEL/1873", receiver has extended gas ports and thicker walls. Smooth trigger. Boxed script "SWP/1882" (Samuel W. Porter) inspection cartouche on the left of the stock wrist. Long wrist stock with the short comb. The lock plate and barrel both have the standard proofmarks and markings. "GDM" (George D. Moller) collection initials marked at the toe of the stock. Includes period leather sling. These rare Model 1882 Trapdoor rifles are described and pictured on pages 130-135 of the book "The 45-70 Springfield" by Frasca & Hill. Certainly one of the rarest of all the models of Trapdoors, of which almost none are known to exist today. Provenance: The George Moller Collection