It is probably the best-known weapon in the world, brandished by everyone from Che Guevara to Osama bin Laden. But the Kalashnikov assault rifle has failed to produce a profit for its makers for years. Things were just starting to improve when the firm was hit by Western sanctions. With Russian military stores full of the famously durable Kalashnikovs, and dwindling orders from abroad, the company had turned its attention to civilian firearms markets. In January it finally secured a foothold in the biggest of them, sealing a lucrative deal to supply up to 200,000 rifles a year in the...