A Russian company called Test-Oruzhie (Тест-Оружие) has recently released an M1895 Nagant revolver-based carbine dubbed Ten-7 (Тень-7, “Ten” means shadow). As you can see, they fitted the host Nagant revolver with a long barrel (or maybe a fake barrel extension to meet the law requirements) and what looks to be a FAB Defense Glock stock. Also, the revolver is rechambered to 5.45x18mm. Overall, this Nagant carbine looks like a gun from a post-apocalyptic video game.
The 5.45x18mm is a .22 caliber rimless centerfire bottleneck cartridge mostly known as the cartridge of the Russian PSM pistol. It launches a 37-grain FMJ bullet to a muzzle velocity of about 1,000 fps when fired from a PSM pistol. You can download the CIP specs of this cartridge by clicking HERE.
I am sure there is a reason this gun has been rechambered to 5.45×18 (law, ammunition availability, state of the host guns, etc), but that kind of conversion will result in partial loss of arguably the main feature of Nagant revolvers – the cylinder gap seal achieved by the forward movement of the cylinder and telescoped cartridge case which mouth extends into the barrel and seals it as it expands during firing the gun. I suppose the forward movement of the cylinder will still decrease the amount of escaping gasses to some extent. IzhMash used to make a Nagant carbine chambered in .22 LR (KR-22 Sokol (КР-22 Сокол)) which had redesigned cylinder/barrel mating surfaces to ensure a more tight seal despite the use of non-telescoped case ammunition. Maybe the Ten-7 carbine also utilizes a similar design adjustment.
That sealed cylinder gap feature makes the M1895 Nagant revolver chambered in the original 7.62x38mmR cartridge a great candidate for carbine conversions because the cylinder gap has been a major issue for revolving carbines and probably the main reason they never gained any significant popularity. Actually, previously there have been Nagant revolver carbine conversions in Russia. Tula plant made such guns for Imperial Russian border patrol and engineer units at the beginning of the 19th century. There is even a Nagant revolver with a boarding ax used as a detachable stock which was reportedly an experimental gun for the Imperial Russian Navy. There are also countless one-off custom conversions done both in Russia and other countries.
What do you think about the idea of converting a Nagant revolver into a carbine? Sounds like a great project, doesn’t it? Just make sure such conversion complies with your local laws.
Images from www.test-guns.ru