Nightcrawler
Member
I've heard repeated several times that once ballistic projectiles reach a certain velocity (higher than what current rifles are capable of), the achieve a wounding capacity far greater than their size would suggest, making bullet mass much less important.
I've heard elsewhere that when objects reach about 3,000 meters per second in velocity, they tend to hit with a force roughly equivalent that same amount of mass of TNT detonating on the target.
3,000 meters per second (roughly 9,482 feet per second) is a little on the high velocity side for a shoulder fired weapon. So let's set our velocity at 2,000 meters per second (6,561 fps). This is what David Weber uses for the pulser rifles in his Honor Harrington series of novels. These weapons use a small gravitic accelerator (believable in a society that has mastered anti-gravity and gravitic propulsion) to propell a solid or explosive dart to high velocity. Some of these weapons have three barrels and selective magazines and are capable of high rates of fire.
So, let's say Nightcrawler Tactical has made a breakthrough (okay, we stole it from some Japanese scientists) in room-temperature superconductors, and are using some next-generation power sources we stole from somebody else.
We can now make a magnetic accelerator rifle. That is to say, a coil gun.
The weapon we designed uses this electromagnetic coil to propell a tungsten flechette, long and finned for stability, 4.5mm in diameter, to 2,000 meters per second. The projectile weighs 20 grains.
According to this handy muzzle energy calculator, that would give us 1,912 foot-pounds of energy at the muzzle, or 2,600 joules for you crazy Metric types. The projectile would have a sectional density of 0.091.
For comparison, a 55-grain .223 round has a muzzle velocity of roughly 3,240 fps, for an energy of 1,282 foot-pounds (1743 J), with a sectional density of 0.157.
The only real modern attempt at a flechette rifle, the Steyr ACR, pushed a roughly 10 grain dart to a palsy 5,000 feet per second. I have serious doubts about the ACR's effectiveness and penetration, due to the lightweight projectile. I don't think the velocity hits the threshhold where velocity itself becomes a wounding mechanism.
Anydangway, I don't think the recoil of my flechette rifle would be anything close to being unmanagable. You could probably even up the grainage a bit and maintain the same velocity without it being uncomfortable. Even at high velocity, lightweight projectiles are ususally easy on the recoil. Note frangible, high-velocity handgun rounds for comparison.
So, am I understanding the physics correctly here? IS there a velocity threshhold where, once crossed, kinetic energy in of itself becomes a significant wounding mechanism? Would 2,000 meters per second be sufficient?
I know that this works in theory. Tank projectiles blow up enemy tanks without using any explosive. The kinetic energy turns the projectile to molten goo and roasts everything inside the enemy tank. But a tank projectile has a lot more mass and velocity than what I'm talking about here.
Oh, and not to be rude, but skip the obligatory comments about overpenetration. This would be a battlefield weapon, where being able to shoot through walls, cars, armor, and equipment is a significant advantage.
It'd also be extemely flat-shooting.
I wonder, though, would it be effective? If so, I think a 6mm heavy flechette rifle (probably semiautomatic only) might be in the works...
I've heard elsewhere that when objects reach about 3,000 meters per second in velocity, they tend to hit with a force roughly equivalent that same amount of mass of TNT detonating on the target.
3,000 meters per second (roughly 9,482 feet per second) is a little on the high velocity side for a shoulder fired weapon. So let's set our velocity at 2,000 meters per second (6,561 fps). This is what David Weber uses for the pulser rifles in his Honor Harrington series of novels. These weapons use a small gravitic accelerator (believable in a society that has mastered anti-gravity and gravitic propulsion) to propell a solid or explosive dart to high velocity. Some of these weapons have three barrels and selective magazines and are capable of high rates of fire.
So, let's say Nightcrawler Tactical has made a breakthrough (okay, we stole it from some Japanese scientists) in room-temperature superconductors, and are using some next-generation power sources we stole from somebody else.
We can now make a magnetic accelerator rifle. That is to say, a coil gun.
The weapon we designed uses this electromagnetic coil to propell a tungsten flechette, long and finned for stability, 4.5mm in diameter, to 2,000 meters per second. The projectile weighs 20 grains.
According to this handy muzzle energy calculator, that would give us 1,912 foot-pounds of energy at the muzzle, or 2,600 joules for you crazy Metric types. The projectile would have a sectional density of 0.091.
For comparison, a 55-grain .223 round has a muzzle velocity of roughly 3,240 fps, for an energy of 1,282 foot-pounds (1743 J), with a sectional density of 0.157.
The only real modern attempt at a flechette rifle, the Steyr ACR, pushed a roughly 10 grain dart to a palsy 5,000 feet per second. I have serious doubts about the ACR's effectiveness and penetration, due to the lightweight projectile. I don't think the velocity hits the threshhold where velocity itself becomes a wounding mechanism.
Anydangway, I don't think the recoil of my flechette rifle would be anything close to being unmanagable. You could probably even up the grainage a bit and maintain the same velocity without it being uncomfortable. Even at high velocity, lightweight projectiles are ususally easy on the recoil. Note frangible, high-velocity handgun rounds for comparison.
So, am I understanding the physics correctly here? IS there a velocity threshhold where, once crossed, kinetic energy in of itself becomes a significant wounding mechanism? Would 2,000 meters per second be sufficient?
I know that this works in theory. Tank projectiles blow up enemy tanks without using any explosive. The kinetic energy turns the projectile to molten goo and roasts everything inside the enemy tank. But a tank projectile has a lot more mass and velocity than what I'm talking about here.
Oh, and not to be rude, but skip the obligatory comments about overpenetration. This would be a battlefield weapon, where being able to shoot through walls, cars, armor, and equipment is a significant advantage.
It'd also be extemely flat-shooting.
I wonder, though, would it be effective? If so, I think a 6mm heavy flechette rifle (probably semiautomatic only) might be in the works...