Long a mysterious unknown member of the Martini family, the Nepalese Gahendra rifles finally became available in the US and Europe after IMA purchased Nepal’s cache of historic arms. The Gahendra is a uniquely Nepalese design built to sidestep British reluctance to supply military arms to the colony. Developed by a General Gahendra (who is also responsible for the Bira copy of the Gardner Gun), the rifle is not actually a Martini at all. Instead, it shares its mechanical features mostly with the earlier Peabody falling block rifles, using a hammer and flat mainspring (the Martini improvement replaces there with a striker and coil spring).
Gahendras are chambered for the standard British .577/.450 Martini cartridge, although their bore diameters vary substantially, and one should absolutely slug a specific rifle before loading ammunition for it. In fact, unless you are capable of proficiently assessing the safety of the Gahendra, it is wiser not to shoot them at all. These rifles were individually handmade well over a hundred years ago using steels of questionable metallurgy and hardening.
That said, the guns were actually much better made than most people assume, considering their non-interchangeable parts. Craftsmen built each rifle part by part, giving the factory an output of just 4 rifles per day. Production began in the 1880s, and according to the Nepalese government ended prior to 1899. Dates on the rifles, however, are commonly found as late as 1911. These dates are generally assumed to be inventory or refurbishment dates.