A question about guns.

[Ford Prefect]

Now, as I so dutifully discovered when I first arrived at the main site, at ranges over a hundred metres, a round from a standard issue military handgun drops more than two and a half feet.

Naturally, handguns aren't meant to be used at long ranges, but is it at all conceivable that we could one day reduce this problem in any way?

[Shroom Man 777]

Targetting computer things? Basically, you compensate by aiming the gun high or something - like a howitzer or something. Not that it would be practical.

[Ender]

Now, as I so dutifully discovered when I first arrived at the main site, at ranges over a hundred metres, a round from a standard issue military handgun drops more than two and a half feet.

Naturally, handguns aren't meant to be used at long ranges, but is it at all conceivable that we could one day reduce this problem in any way?

You can reduce it by making the bullet go faster. It would be further away when it has dropped that much. Other then that, no seeing as how the cause is gravity.

[Glimmervoid]

Now, as I so dutifully discovered when I first arrived at the main site, at ranges over a hundred metres, a round from a standard issue military handgun drops more than two and a half feet.

Naturally, handguns aren't meant to be used at long ranges, but is it at all conceivable that we could one day reduce this problem in any way?

You can reduce it by making the bullet go faster. It would be further away when it has dropped that much. Other then that, no seeing as how the cause is gravity.

If you got a bullet going a speed so that it was falling at the same rate as the earths curve was dropping out below the bullet you could completely eliminate the problem. Well you could never totally get rid of it because the earth is not a perfect globe (even with mountains/hills cut off) there would still be some but all most.

[wilfulton]

It depends on the rifle, the cartridge, but most importantly, the bullet itself. Rifle bullets tend to be long and skinny, having a much greater length to diameter ration than pistol bullets, resulting a better ballistic coefficient, which means they don't slow down as quickly due to wind resistance. In addition, most rifle bullets exit around 2500-3500 feet per second (the higher range being more common for smaller calibers). They also make "accelerator" rounds rifles like my .30-06, which utilize a sabot to fire a subcaliber bullet at much higher velocity, in excess of 4000 feet per second. These cartridges are intended for long range varmint hunting, as they have a very flat trajectory (less drop = easier to hit a small target such as a ground squirrel), a result of their high velocity

Pistol rounds exit at much lower velocity, around 800 to 1400 feet per second. The low end is about the .45 ACP, and the higher end is a hot load for a .44 magnum. Cartridges like the 9mm and .40 S&W generate around 1100 feet per second, so the bullet is going to have a much longer flight time, and thus drops much farther due to gravity. Also, the short, fat nature of pistol rounds means they have more surface area for the air to push against as opposed to mass to keep them going, so they'll also slow down due to wind resistance faster than a rifle bullet of similar weight.

The other problem with handguns is the short sight base. The longer distance between front and rear sights on a rifle means that minor errors in aim are more noticeable to the holder, and he can better correct for them. A pistol's sights are designed for close range shooting, whereas a rifle's are intended for long range. That is about as simplistic an explanation as you're apt to find, but a handgun will never be able to engage targets at long range, although at least one previous denizen of the sewer had at one point claimed otherwise (read Mike's hate mail under Stewart Davies, 'nuff said.)

[sketerpot]

If you got a bullet going a speed so that it was falling at the same rate as the earths curve was dropping out below the bullet you could completely eliminate the problem. Well you could never totally get rid of it because the earth is not a perfect globe (even with mountains/hills cut off) there would still be some but all most.

Only if you disregard air resistance, which would slow the bullet down and cause it to fall.

[Glimmervoid]

Only if you disregard air resistance, which would slow the bullet down and cause it to fall.

Yer you right sorry did not think of that.

[Lusankya]

If you got a bullet going a speed so that it was falling at the same rate as the earths curve was dropping out below the bullet you could completely eliminate the problem. Well you could never totally get rid of it because the earth is not a perfect globe (even with mountains/hills cut off) there would still be some but all most.

Only if you disregard air resistance, which would slow the bullet down and cause it to fall.

And even then, it still wouldn't go in a straight line because the Earth's surface is curved. To get a bullet that didn't "drop down" according to your eye, you would have to find one that resisted gravity.

[Einhander Sn0m4n]

How many seconds does it take for the projectile to travel to the target? Each second it's accelerated by gravity at 9.8m/s^2.

The equation for this, solving for distance, (bear with me, I'm new at this) is D=1/2AT^2 (Distance equals one half acceleration times time squared).

Let's solve for a three-second flight time.

1/2(9.8)(3)^2=44.1

So, if it takes three seconds to travel, the projectile drops 44.1 meters.



Yes, I suck at math... :)

[Einhander Sn0m4n]

GH3TT0 EDIT: The equation above ignores air resistance, ballistic coefficients, et cetera, so this is only a rough calculation. </Disclaimer>

[Einhander Sn0m4n]

EDIT TWO: Can someone kill the damn smiley in my equation par favor?

[sketerpot]

1/2(9.8)(3)^2=44.1

So, if it takes three seconds to travel, the projectile drops 44.1 meters.

That's assuming that the bullet is shot straight perpendicular to the force of gravity, and therefore does not have any initial velocity up or down.

[Einhander Sn0m4n]

1/2(9.(3)^2=44.1

So, if it takes three seconds to travel, the projectile drops 44.1 meters.

That's assuming that the bullet is shot straight perpendicular to the force of gravity, and therefore does not have any initial velocity up or down.

But can the 44.1 meters' drop be measured from the point at which the bore was aimed, regardless of angles other than directly up and directly down? I'd imagine gravity would have the same force on the projectile if it were aimed perpendicular to the gravity force vector or at an angle to it. So really we're solving for the projectile's drop from the trajectory it would take if gravity weren't accelerating it at all.

[sketerpot]

1/2(9.8)(3)^2=44.1

So, if it takes three seconds to travel, the projectile drops 44.1 meters.

That's assuming that the bullet is shot straight perpendicular to the force of gravity, and therefore does not have any initial velocity up or down.

But can the 44.1 meters' drop be measured from the point at which the bore was aimed, regardless of angles other than directly up and directly down? I'd imagine gravity would have the same force on the projectile if it were aimed perpendicular to the gravity force vector or at an angle to it. So really we're solving for the projectile's drop from the trajectory it would take if gravity weren't accelerating it at all.

Gravity would have the same force, but you'd have to include the vertical component of the initial velocity of the bullet in your equation.

Δy = 1/2(9.81)(3)^2 + 3v*sin(θ)

Where Δy is the change in the altitude of the bullet after 3 seconds, v is the initial speed of the bullet, and θ is the angle of the gun above horizontal.

Think about it this way: if you shoot a bullet upward with enough velocity that it takes more than 3 seconds to reach the top of its trajectory, it will not have dropped at all because of gravity after 3 seconds. It will just have climbed slower. This is an extreme example, but in all cases you'll have some initial velocity up or down.

-------

In case you're interested (and because I'm bored), I'll derive the full form of the formula you were using. If you're not interested, feel free to skip the rest of this post.

First, you need to understand how position (s), velocity (v), and acceleration (a) are related. Velocity is the rate of change of position, acceleration is the rate of change of velocity. Using calculus and those definitions, we can get this formula for velocity after applying constant acceleration for t seconds:

v(t) = at + v_i

The velocity at time t equals acceleration times t plus the initial velocity. Now we can get the formula for position:

s(t) = 1/2*a*t^2 + v_i*t + s_i

In the formula above, s_i is the initial position. We can rearrange things a little to say:

Δs = 1/2*a*t^2 + v_i*t

Where Δs is the change in position. This is what you need to use to calculate change in position with constant acceleration and an initial velocity.

[lPeregrine]

Now, as I so dutifully discovered when I first arrived at the main site, at ranges over a hundred metres, a round from a standard issue military handgun drops more than two and a half feet.

Naturally, handguns aren't meant to be used at long ranges, but is it at all conceivable that we could one day reduce this problem in any way?

Not really, unless you want to have broken wrists from firing it. The bullet drops at the same rate no matter how fast it's going horizontally (9.8m/s^2). Faster bullets drop less over distance because it takes them less time to cover that distance. A rifle bullet might only drop a few inches (imaginary number) over that 100m, because it took a tiny fraction of the time to get there. When it's traveled for as much time as the pistol round takes to get 100m, it'll have dropped 2.5' too.

So the only real way to make the drop less of a problem is to get the bullet to its target faster. Sounds easy enough, just use a more powerful caliber. But a pistol has very little weight to counter recoil. So every bit of velocity increase you get is going to come at the price of increasing recoil, to the point that the weapon becomes useless for its intended purpose. There's a good reason those rifle-caliber pistols are an interesting toy, not a serious military weapon.

And it's true that you can reduce that to some degree by using smaller bullets, but a 2mm bullet is pretty useless.

[Sea Skimmer]

But can the 44.1 meters' drop be measured from the point at which the bore was aimed, regardless of angles other than directly up and directly down? I'd imagine gravity would have the same force on the projectile if it were aimed perpendicular to the gravity force vector or at an angle to it. So really we're solving for the projectile's drop from the trajectory it would take if gravity weren't accelerating it at all.

Aiming at an angle does produce longer range, but using the sights on a typical handgun, you can't elevate the barrel very much at all before you'll lose sight of the target. Higher performances guns (where talking artillery here) also get maximum range from much higher elevations, up to 55 degrees. This is in comparison to lower power weapons like rifles and machine guns, because throwing the shell up to a very high altitude greatly reduces air resistance. A rifle projectile meanwhile would never get high enough to gain an advantage.

[The Dark]

If only someone could get the gyrojet pistol to work properly, it'd make things interesting. The original was basically a 13mm rocket launcher, with a slug as the warhead. Muzzle velocity was only 900 fps, but IIRC it accelerated a good bit once it exited the muzzle.

[Winston Blake]

As has been mentioned, what you want is higher velocities, but that results in impractical recoil. However, flechettes are both high velocity and low recoil, which allows very high penetration, accuracy and rate-of-fire.

E.g. the Steyr ACR:

Due to extremely high projectile velocity, flight time was very short at any practical ranges, and trajectory was wery flat, giving the shooter almost ray-gun performance, which allowed to fire withouth prior calculations of point of impact - speaking simply, at any practical combat ranges shooter will hit where it aimed, regardless target movements (projectile flight time to the target at 300 meters is about 0.2 seconds)

Apply the same principles to a handgun and voila! OTOH, flechette weapons have some problems of their own, not the least of which is the world being already drenched in conventional ammunition.

If you're trying to work out futuristic guns for a scifi setting, you could go all the way and make them caseless too cf the G-11.

[Pu-239]

Well, you could modify the bullets to generate lift and put it inside a sabot to be fired from a smoothbore, but then you'd have the problem of too much or too little lift, depending on air conditions- you'd be better off w/ a conventional sabot.

[Winston Blake]

Well, you could modify the bullets to generate lift and put it inside a sabot to be fired from a smoothbore, but then you'd have the problem of too much or too little lift, depending on air conditions- you'd be better off w/ a conventional sabot.

Ah, you see, but then all you need is a control chip in each bullet that dynamically adapts to all conditions and adjusts the proportions of tiny maneuvering jets. Absurdly impractical and expensive, no doubt a multibillion-dollar american program will be started to investigate the idea, which'll be cancelled at 95% completion and ahelluvalot% overbudget and overdue.

[Sea Skimmer]

Apply the same principles to a handgun and voila! OTOH, flechette weapons have some problems of their own, not the least of which is the world being already drenched in conventional ammunition.

Also the rather massive issue that all the weapon will do to a human body is punch small holes clear through it. The result will be that while the weapon may be lethal, it won't produce anything like instant incapacitation, which is what you absolutely want from a handgun or rifle. A flechette-firing pistol would probably make .22LR look suitable for hunting bears.

As for caseless ammunition, it introduces some major problems with sealing the gun breach and heat dissipation, normally cartridge cases do both tasks. The G11 required some fancy design work (which makes the gun much more expensive) to solve the former issue, and they had to use a different and more expensive propellent in ordered to avoid cook offs from the heat buildup.

[Winston Blake]

Apply the same principles to a handgun and voila! OTOH, flechette weapons have some problems of their own, not the least of which is the world being already drenched in conventional ammunition.

Also the rather massive issue that all the weapon will do to a human body is punch small holes clear through it. The result will be that while the weapon may be lethal, it won't produce anything like instant incapacitation, which is what you absolutely want from a handgun or rifle.

Yes i should've mentioned that. Although... given a setting without our political restrictions on expanding projectiles, wouldn't it be possible to have hollow point variants that give stopping power similar to bullets (against unarmoured targets)? Also the SCIMTR flechette design is a flat shape that apparently can make "larger, more disabling wounds".

BTW how practical would it be to have a gun with two flechette magazines (armor-piercing and hollow-point)? Is the increased versatility too far outweighed by the logistics problems and possible soldier confusion?

As for caseless ammunition, it introduces some major problems with sealing the gun breach and heat dissipation, normally cartridge cases do both tasks. The G11 required some fancy design work (which makes the gun much more expensive) to solve the former issue, and they had to use a different and more expensive propellent in ordered to avoid cook offs from the heat buildup.

Yeah, but that was more of a suggestion for a futuristic scifi setting, presumably where that higher cost isn't as big a disadvantage any more.

[Ford Prefect]

I was actually asking because I was writing about someone making an incredibly long shot in my story *cough* shameless plug *cough* with a handgun, and I just remembered that whole thing about how handguns were not designed for making such incredibly long shots. I'm able to chalk it up to being the Future(tm) and all, but it got me wondering what could be done if you didn't had the requisite advanced technology of the Future(tm).

And this thread has been very interesting, so please do continue.

[Winston Blake]

I was actually asking because I was writing about someone making an incredibly long shot in my story *cough* shameless plug *cough* with a handgun, and I just remembered that whole thing about how handguns were not designed for making such incredibly long shots. I'm able to chalk it up to being the Future(tm) and all, but it got me wondering what could be done if you didn't had the requisite advanced technology of the Future(tm).

How long is incredibly long? Too far and the person will never be able to make the shot no matter how accurate or long-ranged the gun technology is, since humans just can't hold it steady enough. Maybe a stock (ideally folding out) might be enough to make your scenario work.

[Ford Prefect]

Incredibly long is about a hundred and twenty metres. My narration calls it a fluke shot, and I'm inclined to believe it.