"A Gun for Dinosaur" is a classic time travel science fiction story written by L. Sprague de Camp as part of his Rivers of Time series. It tells the story of four men who travel into the past to hunt and kill dinosaurs.
It was first published in the magazine Galaxy Science Fiction for March, 1956, and first appeared in book form in the anthology The World That Couldn't Be and 8 Other SF Novelets (Doubleday, 1959). It has since been reprinted in numerous other anthologies, including The Time Curve (1968), 3000 Years of Fantasy and Science Fiction (1972), Dawn of Time (1979), Science Fiction A to Z (1982), Grand Masters' Choice (1989), Dinosaurs! (1990), Dinosaurs (1996), Timescapes: Stories of Time Travel (1997), The SFWA Grand Masters, Volume 1 (1999), The World Turned Upside Down (2005), and The Best Time Travel Stories of the 20th Century (2005), as well as such collections of de Camp's work as A Gun for Dinosaur and Other Imaginative Tales (1963), The Best of L. Sprague de Camp (1978), Rivers of Time (1993), and Years in the Making: the Time-Travel Stories of L. Sprague de Camp (2005). It has been translated into French, German, Italian, Czech, Dutch, and Spanish, and adapted into radio and comic book form.
The story takes the form of a first-person narrative by the protagonist, time-traveling hunter Reginald Rivers told to Mr. Seligman, a prospective client of his time safari business; Seligman's contributions to the conversation are omitted, and must be inferred from those of Rivers. Rivers informs the client he is not big enough to hunt the dinosaurs of the Cretaceous period, illustrating his point with an extended anecdote from a previous expedition, which forms the main portion of the tale.
On the occasion in question, Rivers and his partner Chandra Aiyar conduct two other clients to the past. One of them, Courtney James (based on Jack Parsons), is a vain, arrogant and spoiled playboy; the other, August Holtzinger, is a small, timid man recently come into wealth (time safaris are not cheap). Before the journey, they test-fire some guns on the firing range to settle on weapons for each of them. Holtzinger's small size makes him incapable of effectively handling a heavy-caliber weapon (the recoil knocks him over) and, against his better judgment, Rivers lets Holtzinger travel on the safari with a lighter caliber weapon.
James proves unmanageable, shooting at every creature in sight and spoiling Holtzinger's shots. Ultimately James' foolishness gets him in real trouble, when he inadvertently empties his rifle over a slumbering Tyrannosaurus, which consequently wakes and makes for him. Holtzinger defends James by shooting the dinosaur, but his gun is not powerful enough to kill it, and his act only attracts it toward the shooter. Despite the best efforts of Rivers and Aiyar to save Holtzinger, the Tyrannosaurus snaps him up and makes off with him. A furious quarrel with James ensues, he and the guides each blaming the other for their companion's death. James tries to kill Rivers, but is knocked out by Aiyar. Afterwards he swears revenge.
Later, after the expedition has returned to the present, James bribes Professor Prochaska, the scientist operating the time chamber, to send him back to the Cretaceous again—but at a point just prior to the emergence of the safari's earlier visit. His plan is to shoot Rivers the moment the latter originally came out of the time machine. Since that obviously had not happened, however, the space-time continuum avoids the paradox by spontaneously snapping James back to the present, the forces involved instantly killing him.
Concluding his tale, Rivers makes his point with Seligman by emphasizing Holtzinger's fate.
De Camp revised the story slightly for its inclusion in Rivers of Time to update obsolete paleontological terms and dated references. In one instance the result was unfortunate; in the original version of the story, Rivers estimates Seligman's weight in both pounds and stone; in the revised version both measures are rendered as kilograms, resulting in Rivers appearing to make the same calculation twice.
Many years after writing the story, de Camp penned eight more tales of its protagonist, time-traveling hunter Reginald Rivers; all nine stories were then collected as Rivers of Time (1993). A tenth tale of Rivers, "Gun, Not for Dinosaur", authored by Chris Bunch, later appeared in Harry Turtledove's 2005 tribute anthology honoring L. Sprague de Camp, The Enchanter Completed.
P. Schuyler Miller singles out the story as "one of the classic time-travel stories invading the years of the dinosaurs."
S. E. Cotts calls it "one of my favorites," noting that "[i]ts subject, about a safari into the past, has been successfully tackled by other writers, but this version has solid merit."
Sam Moskowitz, who felt de Camp's ... plots less incisive" during this period, cited this story as an "outstanding exception" discussing "with an air of quiet authority the problem of what type of gun and what methodology were best suited to shooting dinosaurs."
Don D'Ammassa calls it "an undeniably classic story of the dangers of time travel."
Harry Turtledove deems the piece a "classic, ... at the same time a fine character study, a meditation on time-travel paradoxes (here treated as something the continuum seeks to avoid rather than a likely result of voyaging into the past), and a splendid re-creation of a vanished world. De Camp makes the reader feel the heat and humidity of the world to which Reginald Rivers and his band of hunters are transported--and feel the bites from insects with mouthparts evolved to pierce dinosaur hide. He does a masterful job of discussing the difficulties inherent in hunting extinct behemoths with weapons small enough for one man to handle. When troubles arise, they do so as a natural consequence of the characters' personalities, and are more moving and convincing because of that." He feels the story "has also aged very well, despite the vast increase in paleontological knowledge in the past half-century."Mark B. Goodwin claims de Camp's story "popularized the idea that pachycephalosaurs used their domed skulls as a kind of battering ram," a notion first suggested as "a wild idea" by vertebrate paleontologist Edwin H. Colbert in 1955. (The pachycephalosaur episode appears on pages 14–15 of the story as published in Rivers of Time.)
David Drake in his 1981 story "Time Safari", uses a very similar set of characters and events. In "Time Safari", the guide character dismisses as a misconception a significant point (to both stories) about the need for a sufficiently large gun to kill a dinosaur, thus contradicting the earlier story.
Author Leonard Richardson mentions his disappointment that this story "is not about a dinosaur who buys a gun" as one of his influences in writing his own 2009 short story, "Let Us Now Praise Awesome Dinosaurs."
A Gun for Dinosaur on X Minus One, NBC radio, 1956