The Mauser Construktion 96, or C96, entered service in 1896 and was made– barring Chinese and Spanish unlicenced copies– into the late 1930s for both the consumer market and military contracts. While the standard barrel length of the “Broomhandle” was 5.5-inches, and shortened “Bolo” length guns ran 3.9-inchers, there are a few that went significantly longer.
The M1896 Kavallerie Karabiner, made for just three years, ran a 15-inch barrel with a permanently affixed wooden stock and forend. This was later repeated briefly in the M1917 Mauser trench carbine proposal during the Great War that never reached production.
Then came the 12-inch Karabiner pistols, with detachable stocks.
During the 1980s and 90s, Navy Arms custom made a few batches of faux Karabiners in rifle format, complete with fixed stocks and 16.25-inch barrels to keep them NFA legal.
Morphy’s Auction House has been specializing in these long boys for a minute, having sold several over the years.
Morphy also in 2019 auctioned a one-of-a-kind engraved C96, complete with a 12 inch, slightly heavier custom barrel that was made by the Bohler steel company of Austria.
Then there is this, in the current Morphy Collectible Firearms & Militaria auction, running this week.
Bidding is within my range, currently, so maybe we’ll get to bring this one home.