The Gun Runners

George Dolan had four immediate problems: the time-translator, a beautiful, out-of-this-world girl named Moirta, the gun runners and his life. A situation in which he finally triumphed.... But what can you do with a victory that lies at the other end of a bridge 10,000 years long?
The gun runners were professionals, and except for one minor detail the operation had been very well planned.
The middle twentieth century was chosen as a source of supply after a careful survey of all factors pro and con. The gun runners did not want the mass weapons of their own day, they wanted selective weapons which could be used for private murder. In the mid-twentieth century, the level of technology was such that well-made and reliable weapons were available; and at the same time, social control was still sketchy enough to permit quiet procurement of such merchandise, if one knew how to go about it and was suitably financed.
The gun runners, two men and a woman, knew how to go about it, and they were suitably financed. The profits in their business were commensurate with the risks—which were not small.
In their world unauthorized time travel was highly illegal, because of certain possible undesirable effects on the total space-time continuum, and was severely punished. Moreover, it was personally uncomfortable and dangerous.
They came from an old ingrowing world which had never reached the stars, where there were only men and their works, no blade of grass or micro-organism or sparrow which did not directly serve men. In their time, hereditary traits which had meant untimely and certain death in earlier times had persisted and multiplied. Immunities and instincts which had fitted men to live with tigers and streptococci, and seek their food in the wilderness, had atrophied.
The twentieth century was a dangerous environment for these people, more so perhaps than the Eocene would have been for homo sapiens . In preparation for their venture, it had been necessary for them to undergo a drastic and painful series of tests, inoculations, conditionings and plastic surgery.