Rose McGowan as Cherry Darling in “Planet Terror” (2007).

Occasionally, filmmakers take extra care to get guns right in a movie or on TV. Far more often, they go with what looks cool, never mind how ungainly, unsafe, or impractical such a gun might be in real life. Here are five of the worst—four from the movies and one from TV. With the exception of number one, which is just plain idiotic, they all look really cool…they just wouldn’t work in real life. Given the number of guns in movies, I am sure this is hardly an exhaustive list, but here are mine:

1. Rose McGowan’s Bushmaster from “Planet Terror”

Cherry Darling (Rose McGowan) replaces her severed leg with a Bushmaster carbine fitted with a Cobray 37mm Launcher in Robert Rodriguez’s “Planet Terror” (2007).

You are a nuttier gun nut than me if you think a stripper with a Bushmaster (with a Cobray grenade launcher) as a prosthetic leg is either hot or cool. It’s just dumb. You know, if she had a gun as a prosthetic arm, I could see it, but as a leg? Walking on your rifle’s muzzle is as great way to plug it with mud and dirt. Also, I realize this is science fiction/fantasy, but how does she pull the trigger? Unquestionably, this is the stupidest gun in movie history.

2. Arnold’s Rail Guns from “Eraser”

Arnold Schwarzenegger wields dual rail guns as U.S. Marshal John Kruger in “Eraser” (1996).

Railguns exist now as experimental weapons; the Navy hopes to begin sea trials with a gun capable of accurately firing projectiles at ranges of 100 miles later this year. Railguns create an electromagnetic field on two rails. A conductive projectile completes the circuit, and something called a Lorentz Force sends it off the rails at incredibly high speed. The railguns in Eraser are supposed to shoot their aluminum bullets at nearly the speed of light. That means: 1) Recoil would be fatal to the shooter, and 2) air resistance would ignite the bullet almost immediately. Railguns generate massive amounts of heat, probably more than even a Governator could stand to hold onto. And yet, Arnold is able to shoot one with each hand. Bonus: check out the nifty X-Ray scope.

3. Jesse Ventura’s Minigun in “Predator”

Jesse Ventura as Blain carrying a minigun modified to be hand-held in “Predator” (1987). It’s the same minigun co-star Arnold Schwarzenegger later uses in “Terminator 2: Judgement Day” (1991).

As a member of a commando team, Ventura humps a 7.62 caliber minigun around the jungle. Besides the problem of hauling enough ammunition to feed a gun that shoots 166 rounds a second, and the difficulty/impossibility of controlling such a gun by hand, there is also the issue of the king of all hot feet you would get from the cascade of smoking empties. Finally, it takes two truck batteries to run the thing. The filmmakers ran a cable under the actor’s pants leg to off-camera batteries to power the minigun motor.

It is worth noting, however, that since “Predator” came out in 1987, smaller and smaller miniguns have been made, many of which can be fired by hand, although you would still have to haul a battery and a couple hundred pounds of ammunition through the jungle.

4. Clint Eastwood’s Harpoon Gun in “The Dead Pool”

Clint Eastwood in the final Dirty Harry installment as San Francisco Inspector Harry Callahan with a giant harpoon gun in “The Dead Pool” (1988).

What to do when the bad guy steals your .44 magnum? Simple. Take a nearby harpoon gun off its deck stanchion and shoot it from the hip. Never mind that in real life, the recoil of shooting a harpoon weighing several pounds would knock you down and maybe break some bones. But, because this is a movie, all that happens is Harry delivers the worst catchphrase of the series: “You’re s*** outta luck” before impaling the villain, recovering his piece, and coolly walking away.

In the “Dead Pool,” the harpoon gun is a movie prop. Given that real, firing guns are strictly forbidden on movie sets for the safety of the cast and crew, and that the movie guns are carefully watched over by propmasters, it seems highly unlikely that anyone would leave a loaded harpoon gun lying around a movie set after hours. Incidentally, Slash from Guns ‘n’ Roses has a cameo as a harpoon gunner.

5. Steve McQueen’s Mare’s Leg from “Wanted: Dead or Alive”

Steve McQueen as Josh Randall in the classic TV western “Wanted: Dead or Alive” (1958) with his Mare’s Leg rifle, a cut down Winchester 1892 saddle ring carbine chambered in .44-40.

The television series ran from 1958 to 1961, but even today (if you must) you can buy firing replicas of Steve McQueen’s Mare’s Leg, a Winchester Model 92 rifle cut down into a pistol. Besides the recoil of such a gun and the pointlessness of turning a rifle into a pistol, the real reason the Mare’s Leg makes the list is that the gun and ammo don’t match. The rifle is a .44-40, but the small cartridges didn’t look impressive enough in the gun belt on camera, so McQueen wore .45-70 shells instead.

Chiappa makes and sells replica Mare’s Legs. Because it’s illegal to own a rifle with a 12-inch barrel, the Chiappa replicas are chambered for handgun cartridges and are classed as pistols, and are therefore legal to own and shoot. They come in .357 Magnum, .44 Remington Magnum and .45 Long Colt, any of which would be a lot more pleasant to shoot, recoil-wise, than a .45-70.

A Mare’s Leg replica made by Chiappa. It comes chambered in different pistol calibers so it can be classified as a handgun instead of a rifle and remain legal with its 12-inch barrel.