This is a unique example of an experimental/prototype M1 Carbine that was manufactured by the Underwood Elliott-Fisher Company. This is quite possibly the only one ever manufactured as it features a "sliding" recoil absorbing type buttstock design almost identical to the later Winchester Model 12 "Hydro Coil" buttstock used on their trap shotguns. Throughout WWII several of the Defense Companies produced numerous experimental type carbines based on the wartime needs of the U.S. Military. To accomplish that they usually set aside/reserved a specific block of serial numbers usually with a letter prefix of an X, E or both, as preproduction examples or test models. Some concepts were acted on while others became just a prototype that did not get into production. This appears to be one of the later designs. This example is serial numbered "E128" on the heel of the receiver denoting it was an experimental carbine. These carbines were usually assembled from military contract parts and used both early and late production parts with some bearing proofs while others were not. It is estimated that approximately 50-100 carbines were manufactured by several companies, with the majority of the known examples manufactured by the Inland Division and Winchester companies. As noted, this example on the right side of the buttstock is cutaway and is fitted with a sliding outer buttstock shape. Internally it has the sliding mechanism with a fixed wooden buttplate. Internally the machining and parts appear to be original and of the WWII production period and original to the carbine. This carbine has the standard "U.S. CARBINE/M1" markings on the front receiver ring with the rear area stamped "UNDERWOOD/E128", and the barrel is marked "UNDERWOOD/2-43/Ordnance Shell and Flame insignia". Unfortunately we cannot disassemble the actual action as it appears to be attached to the internal mechanism in the stock, hence the theory that it may in fact be an early/original attempt to make a fully automatic carbine. It is fitted with an early type II barrel band, A(without the sling swivel). The receiver is fitted with a blued type 1 flat bolt and a early two-position flip rear sight marked "S" on the side. It has an early all milled trigger housing with a checkered push button safety. It is fitted with an early high wood stock with a very early two-rivet handguard stamped on the underside with a "U" and the very early stylized "Pedersen" type marking. The magazine is blued and marked "IU" on the spine. Provenance: The George Moller Collection

Very fine with 80% of its original green/gray WWII finish with a blued bolt. The stock and handguard are both vey fine showing only very minor handling marks overall with some minor scratches on the left side where the stock slides forward and back. This is a really interesting and possibly one-of-a-kind experimental/prototype M1 carbine that needs further research.