The .50-110 was dropped from the lineup, along with the .45-90, in 1919. I have handled .50-110 Extra lightweight 1886s and they do have very thin barrels at the muzzle end, but also have all the metal that is needed at the breech, where it counts. Serial number information on the 1886 is available from the Cody Firearms Records Office. The have information on serial numbers 1-156599, with some large gaps of missing numbers. Not available are 135125-135144, and 146000-150799. Keep in mind that there are many "contrived" Winchester rifles of all models, not just the '86. Unscrupulous "dealers" will go so far to research a gun's serial number and "build" a gun to meet the specifications. As we all know, you must do your homework when considering the purchase of any antique or older rifle, regardless of the manufacturer.