Lead vs. Rubber Bullets: Which is More Effective in Stopping a Bear?

In summary: If the rubber bullet is much heavier than the lead bullet, it's time for a calculation. Assume a 250 grain bullet at 2500 feet...In summary, the rubber bullet will not bounce back like the lead bullet will and will cause more damage to the bear.
  • #1
Muhammad Danish
70
7
Which bullet of same momentum is more effective in knocking a bear down? Lead bullet or rubber bullet?
 
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  • #2
Muhammad Danish said:
Which bullet of same momentum is more effective in knocking a bear down? Lead bullet or rubber bullet?
What do you think, and why?
 
  • #3
phinds said:
What do you think, and why?
Lead bullet, because it will not compress on hitting the bear whereas rubber bullet will compress..
 
  • #4
Muhammad Danish said:
Lead bullet, because it will not compress on hitting the bear whereas rubber bullet will compress..
I think it's a matter of the rubber bullet not only compressing but rebounding slightly whereas the lead bullet will put all of its momentum into the bear.
 
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  • #5
These explanations confuse me:
upload_2018-7-23_23-30-21.png
 

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  • #6
Muhammad Danish said:
bullet of same momentum

You phrased the question correctly. But you should be aware that a rubber bullet the same size as a lead bullet has less mass, thus less momentum at the same speed. Also, rubber bullets usually have smaller powder charges than lead bullets.

So if your question is purely theoretical about momentum conservation, you're correct. If your question is practical, about real bullets, then there are more factors.
 
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  • #7
Careful here guys; if this is theoretical and the mass is the same and the rubber bullet bounces, then its final momentum is negative, not positive and the momentum transfer therefore is...
 
  • #8
russ_watters said:
Careful here guys; if this is theoretical and the mass is the same and the rubber bullet bounces, then its final momentum is negative, not positive and the momentum transfer therefore is...
The explanation in post #5 suggests that the sign of the result is irrelevant. It is the magnitude of the momentum transfer which matters. That explanation plays pretty fast and loose with signs, but as long as you plug speeds in where velocities are called for, it gets the magnitude of the result right.
 
  • #9
russ_watters said:
Careful here guys; if this is theoretical and the mass is the same and the rubber bullet bounces, then its final momentum is negative, not positive and the momentum transfer therefore is...
Would it not be necessary to take into account the fact that the rubber bullet deforms the bears outer layers, which spring back, but the bullet drives a shock deeper into the body and there's little to no bounce-back. I realize I might not be thinking this through properly, so this is not a rhetorical question.
 
  • #10
phinds said:
Would it not be necessary to take into account the fact that the rubber bullet deforms the bears outer layers, which spring back, but the bullet drives a shock deeper into the body and there's little to no bounce-back. I realize I might not be thinking this through properly, so this is not a rhetorical question.
It appears that the intended result is that the lead bullet passes through the bear while the (larger, more massive, less dense, lower velocity, lower energy but same momentum) rubber bullet fails to penetrate and ultimately bounces back.
 
  • #11
jbriggs444 said:
It appears that the intended result is that the lead bullet passes through the bear while the (larger, more massive, less dense, lower velocity, lower energy but same momentum) rubber bullet fails to penetrate and ultimately bounces back.
Oh, well under that assumption I don't see how there can be any question that the rubber bullet has more body impact, but that's not the assumption I would make. Bear are big damn things.
 
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  • #12
phinds said:
Oh, well under that assumption I don't see how there can be any question that the rubber bullet has more body impact, but that's not the assumption I would make. Bear are big damn things.
Well yes. The momentum of the projectile is not the thing that will successfully stop a charging bear.
 
  • #13
Actually, I hadn't read the embedded photo explanation, but it appears I was pretty close. I had the real bullet embedding, but embed or pass through, it still imparts less momentum than an equal mass and speed rubber bullet that bounces back.
 
  • #14
Isn’t it true that the shock damage is greater from a high velocity low mass bullet?
Not sure exactly constitutes ‘stopping’.
(Just to throw in another idea.)
 
  • #15
I suspect they meant to add that both lead and rubber bullet had same mass an velocity.
 
  • #16
Let us assume that the lead bullet has a typical lead bullet weight of 150 to 300 grains (7000 grains = 1 pound), and further assume that it is traveling at typical lead bullet speed of 2000 to 3000 feet per second. The rubber bullet has the same momentum, so it can be of similar weight traveling at similar speed, or it can be much heavier and traveling at lower speed.

If the rubber bullet has the same weight and speed as the lead bullet, it will penetrate the bear and not bounce back.

If the rubber bullet is much heavier than the lead bullet, it's time for a calculation. Assume a 250 grain bullet at 2500 feet per second, a combination that is about right for bear hunting. The momentum is 2.77 lb-sec. A 10 pound rubber bullet with the same momentum would be traveling 9 feet per second, or 6 miles per hour. It would bounce off, and the bear would probably not even notice.

Neither bullet will "knock the bear down", although the lead bullet is certainly capable of killing and dropping the bear.

And hunting bullets are made from a copper alloy, typically with a lead core.
 

Related to Lead vs. Rubber Bullets: Which is More Effective in Stopping a Bear?

1. What are the differences between lead bullets and rubber bullets?

Lead bullets are typically made from a dense metal, such as lead or copper, and are designed to be fired from firearms. Rubber bullets, on the other hand, are made from a softer material, such as rubber or plastic, and are meant to be non-lethal alternatives to traditional bullets.

2. Are rubber bullets safer than lead bullets?

In terms of lethality, rubber bullets are considered to be safer than lead bullets. However, they can still cause serious injuries, especially at close range or if fired at vulnerable areas of the body.

3. How do lead and rubber bullets impact the environment?

Lead bullets can contaminate soil and water sources with toxic lead, which can harm wildlife and humans. Rubber bullets, while not as harmful to the environment, can still contribute to pollution as they are typically not biodegradable.

4. What are the potential health risks of using lead bullets?

Lead bullets can release toxic lead particles into the air when fired, which can be inhaled by humans and animals. Ingesting lead can also lead to lead poisoning, which can cause serious health issues, especially in children.

5. Are there any alternatives to lead or rubber bullets?

Yes, there are alternative options such as frangible bullets, which are designed to disintegrate on impact and reduce the risk of ricochets and lead exposure. Non-lethal options, such as bean bag rounds and pepper spray rounds, are also available for use in certain situations.

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