Bullets / Ammo That Lose Most of Their Energy (Velocity) In a Few Yards

Status
Not open for further replies.
The only thing that will meet your requirements is a captive projectile, such as an arrow attached to a fishing reel, fired from a crossbow. Or maybe a modified speargun.
 
A very large hollow point (almost a wadcutter), with extremely soft metal/jacket material making up the bullet nose. Once the round exits the bore, the edge of the hollow point has no support and is pulled back (expanding basically) via the air rushing into it at speed. Make the resulting petals long enough and you could have the round almost fall out of the air at set distances.

-Jenrick
 
Velocity bleeds of quickly due to aerodynamic drag.

Best way to get what you want is to apply Battletech physics (ok, that reference isn't gonna make sense to anyone who doesn't play BT, but what the hell)
 
Step :1 Buy a wadcutter mold.
Step :2 Experiment with different dippers to find out how much lead it takes to fill it 1/4 of the way
Step :3 Profit
 
Birdshot and small projectiles lose their energy rather quickly. Now 7.62x39 carries energy well, but it will drop and veer off course. Note that this round is actually about 20% more energetic than 30-30.

Smaller projectiles lose energy more quickly, as described in basic physics.
 
Another point is that the faster the bullet is moving, the more rapidly it will decelerate when it enters a fluid medium as per Newton's 3rd law. Simply put: The harder the bullet hits the target, the harder the target hits the bullet.

Air is basically just that, as is tissue. A fluid. Combine low mass and hyper velocity, and the bullet may not penetrate far enough to do any real good. The bullet has to have a certain amount of mass and momentum in order to penetrate. Radically reducing the mass and trying to make up for it with velocity can easily reach a point of diminishing return.
 
http://www.gunfighter.com/waxbullets/

Inside of 10 feet, U-turned back at me by a bent Phone-book and just propelled by a shotgun primer, A .45 caliber one left a quarter sized bruise under my knee.

They can easily punch clean through several layers of 1970's Ugly wood paneling with the basic charge, I've not tried dumping BP or smokeless into the case, but the rounds can be pushed by a small additional charge.

I'll use them for the odd house Mouse, so I will speak to their Lethality inside of 20 feet ;).

I'd still prefer a Ranger-T, Silvertip, XTP, or DPX and plenty of practice for anything larger.
 
There is Quite a Bit of Confusion These Days

regarding use -- and meanings -- of the terms "Energy," "Momentum," "Power" and "Force".

A projectile causes damage to a target through a transfer of energy, whether that energy is dissipated through simple concussion, or breaking, or tearing, or other damaging actions. The formula for kinetic energy (energy in motion) is one-half the mass times the square of the velocity.

While mass contributes equally with velocity to momentum, momentum is not what we're after; energy is. So when seeking the most damage possible from a projectile, velocity clearly is king.

Of course we need to assure that a really fast-moving projectile doesn't just tear cleanly through the target, but transfers its energy on or within the target, so a flat-nosed projectile moving very rapidly would seem to be getting us closer to what's been asked for here.

Finally, the above suggestion for an aluminum bullet would seem to be helpful, as well. The factor that keeps a projectile moving downrange is momentum, (which can be described as the force necessary to stop a moving object.) Since the only force pushing back against our projectile (except when it hits a target) is that provided by the atmosphere, we want to reduce momentum as much as possible. And since we want a lot of velocity, and velocity contributes one-half of the momentum, while mass provides the other half, then mass would seem to be the factor to reduce, if we want our projectile to run out of steam as soon as possible.

So -- a flat-nosed, light-weight (aluminum?) projectile moving at a very high velocity would seem to be the thing to satisfy the requirement.

But boy, I'd sure want to be extremely careful when trying to work up a load for a very fast aluminum bullet!

But also, I must point out that when working out problems in physics, there always seems to be just one more factor that pokes its nose in at the last minute and throws off all the carefully worked-out conclusions.

So if I've missed something, I certainly won't be miffed when somebody takes the trouble to point it out.
 
I can't help but keep wondering about the military plastic-projectile "practice rounds". They must surely be quite lethal within 30 feet as seen in a home defense situation and would lose velocity very quickly and lose energy extremely quickly after hitting barriers such as walls. Has NO ONE tested these on ballistic gel at close range?
 
AntiSpin has some good thoughts, but keep this in mind if we are going to depend on air resistance to slow down our bullet. Drag varies with the CUBE of the velocity, so the force slowing down the bullet will be greatest at the muzzle and very quickly decrease. We need the opposite in this scenario; we want to bullet to retain velocity until it reaches the predetermined range, then abruptly slow down. We are going to have to have some mechanism to increase drag AFTER the bullet has traveled the predetermined distance. And remember, too, that the bullet must able to stop the threat when it reaches the target. Bullets (or .22 shot shells) that merely injure or annoy the attacker will not sit well with an attorney.
 
Last edited:
There is something that matches the OP's specs
a 40mm Foam Round
close in to vitals it causes MASSIVE internal trauma (sorry but a vest will help, a bit, but not much, plate will help a lot more)
 
get a 500s&w and a piece of 1/2" aluminum rod, a can of fast powder, and some Lee dippers and a hack saw to whack the rod up with. I got all of this but I shot my chronograph. C'est la vie.
 
regarding use -- and meanings -- of the terms "Energy," "Momentum," "Power" and "Force".

A projectile causes damage to a target through a transfer of energy, whether that energy is dissipated through simple concussion, or breaking, or tearing, or other damaging actions. The formula for kinetic energy (energy in motion) is one-half the mass times the square of the velocity.

While mass contributes equally with velocity to momentum, momentum is not what we're after; energy is. So when seeking the most damage possible from a projectile, velocity clearly is king.

Of course we need to assure that a really fast-moving projectile doesn't just tear cleanly through the target, but transfers its energy on or within the target, so a flat-nosed projectile moving very rapidly would seem to be getting us closer to what's been asked for here.

Finally, the above suggestion for an aluminum bullet would seem to be helpful, as well. The factor that keeps a projectile moving downrange is momentum, (which can be described as the force necessary to stop a moving object.) Since the only force pushing back against our projectile (except when it hits a target) is that provided by the atmosphere, we want to reduce momentum as much as possible. And since we want a lot of velocity, and velocity contributes one-half of the momentum, while mass provides the other half, then mass would seem to be the factor to reduce, if we want our projectile to run out of steam as soon as possible.

So -- a flat-nosed, light-weight (aluminum?) projectile moving at a very high velocity would seem to be the thing to satisfy the requirement.

But boy, I'd sure want to be extremely careful when trying to work up a load for a very fast aluminum bullet!

But also, I must point out that when working out problems in physics, there always seems to be just one more factor that pokes its nose in at the last minute and throws off all the carefully worked-out conclusions.

So if I've missed something, I certainly won't be miffed when somebody takes the trouble to point it out.
Click to expand...

Yes, that's all good, but I would like to indicate something very important. Bullets do not magically impart deadly energy just by touching. They have to pass through important structures and make as big a hole in them as possible. Therefore, a somewhat heavier, wider, slower bullet is more lethal than a lighter, narrower, faster bullet simply because it applies its energy to disrupting as wide an area as possible versus poking a hole in the obstruction.
 
22 snake shot to the face will take out the eyes. How is that now a deterrant? I have some 7.62x54r practice ammo, nylon copper clad bullet. They are good to 100 yards or so. I have not shot them at a longer distance. All the flash and bang of a ball load but no recoil.....chris3
 
Why can't we cram some rdx in the hollow point and rig up some kind of fuse so it will explode on contact or after it have gone 100 yards.
 
Status
Not open for further replies.

Similar threads

I
  • Locked
Comparison of velocity and energy downrange.
Replies
3
Views
360
General Geoff
General Geoff
K
  • Locked
Energy, Bullet Weights, & Short Barrels
Replies
11
Views
995
jfh
jfh
hq
  • Locked
Impact velocity
Replies
8
Views
1K
Newtosavage
N
MTMilitiaman
  • Locked
"Effective Range"
2
Replies
27
Views
2K
David Hoback
D
upptick
  • Locked
Kinetic Energy = 1/2Mass times Velocity squared
Replies
10
Views
715
Engineer1911
E
Back
Top