Velocity

[GBG]

What is the free fall terminal velocity of a .310 RB in air?

 

[Norinco]

That shouldn't be hard to calculate.

Terminal velocity is when net force is zero. Force is mass x acceleration. The acceleration of gravity (g) is 9.8 m/s^2 (32 f/s^2). So the force gravity exerts on the ball is its mass times g.

The force of air resistance depends on the speed and a coefficient, which depends on cross sectional area and texture. I do not remember too well how the equations work, but I do remember the force of air resistance can either be linear or quadratic to the velocity.

So you set these two forces equal to each other and solve for the velocity.

 

[GBG]

Drag coefficient for a smooth sphere also varies with velocity and I don't know which value to use.

 

[Zonie]

That's what calculus was invented for. :rotf:

 

[GBG]

For anyone having useful information to share, I'm trying to find out if shooting at tree top squirrels with a .32 poses a danger to other hunters in the area.

 

[necchi]

Oh, I wondered what you were after? :grin:

Well of course it will, but just like all the .22 bullets flyin around too.

If shot straight up ANY projectile will finally stop and begin it's journey back the terra ferma,,at I thinks it's 180 fps. And at that velocity is not fatal but will hurt and leave a lump!
It's when they are shot at a high angle that the projectile will maintain it's velocity and drop back down that things can reach points of causing injury.
Just like any gun, be sure of the back ground before you shoot, this risk is taken with all firearms.
I'd rather be taking my chances with a round ball than a .22 bullet. The Ball will shed it's velocity MUCH faster.

 

[paulvallandigham]

Shooting at any game can pose a threat or risk to other people behind the target. When shooting upwards, your ball or bullet will travel further, so you have to be more aware of the drop zone for that particular caliber and load. If you shoot at a squirrel sitting on a tree root, or on the ground, you risk injuring any person beyond the squirrel on the ground, or coming up out of a ravine, or ditch. Its your responsibility to always know what is beyond your target and ONLY TAKE shots when you know its safe to do so. That is the rule with any gun.

Vice President Richard Cheney shot one of his long time friends in the face and shoulders with shotgun pellets during a Quail hunt in Texas. The friend made a mistake of walking along a deep ravine, to get over to where Cheney and his party were working birds. Cheney thought his friend was with another group hunting in another direction. The friend was. But, he changed his mind without alerting the hunt organizer, who was in charge of the dogs, and was coordinating movements of the two parties. He decided to join Richard after he had flushed the birds and missed the shots. Why he walked where he could not be seen as he approached, is anyone's guess. Cheney was on the end of a drive line, and thought he was clear to shoot anything that got up in front of him, or to his side, and behind him. A bird broke, and flew past him and behind him. It was diving to make the ravine, when Cheney fired, just as his friend's face and shoulder rose up from that same ravine. Cheney could not stop the shot- the timing was too close. Thankfully, they were using rather small bird shot for the hunt, and the friend was not seriously hurt. He did spend a night in the hospital however.

To his credit, Cheney accepted full responsibility for the accidental shooting, as he was the guy who pulled the trigger. This is traditionally who is blamed for any shooting during a hunt. However, its also quite clear that the victim was more at fault for being shot, because of his deviation from the hunt protocol, and failure to remain up on the plain, in full view as he walked over to the other group.

He did not blame Cheney for the shooting, which irritated the Bush haters to no end. The Usual media suspects made fun of Cheney as a hunter for the rest of his term in office, and he took it good-naturedly.

Cheney often left Washington to pursue hunting, which is his recreation. Most of the trips were kept secret from the media. In fact, the media only found out about the shooting in Texas after the woman who organized the hunt for the VP called her local paper to explain the GSW victim in the local hospital.

I have been struck with shotgun pellets fired by shooters on the other end of fields, so far away they could not see me, and I could not see them. I could hear the shots fired, and obviously felt being hit by their pellets, and heard other pellets hitting the leaves of trees around me, but I could not see the shooter.

I also was struck by a pellet in the face that was fired by some hunters on another farm over a hill. I neither could see nor hear them, or the shot, until they came up over the hill.

I have also been struck by ricocheting bullets on more than one occasion.

Give that background a wide angle for additional safety in case a bullet changes direction.

It is not fun to be shot at, either by mistake, or intentionally. I have had both happen to me.

In the case where it was intentional, I fired back. He didn't like being shot at that much either, and ran away. Learn something from that. It might save your life. :hmm:

THERE IS NO SQUIRREL OR OTHER ANIMAL WORTH RISKING INJURING OR KILLING ANOTHER HUNTER, OR SOMEONE ELSE USING THE LAND. When in doubt about the background, or your drop zone, DON'T SHOOT!

Its just that hard a thing to discipline yourself to do. :hmm: :surrender: :thumbsup:

 

[hanshi]

Even a .32 can injure someone same as a .22LR. The .22LR will travel much farther, of course, so it poses even more danger than the .32 prb. The tiny .32 ball may not cause injury of any severity but why take the chance? To be safe it is always prudent to make sure the ball hits something that's able to stop or at least slow it down. If there's no human habitation in the area you hunt, then it doesn't matter what the ball does.

 

[Josh Smith]

Hello,

It's 32ft per second per second (IIRC, could be 60, but I'm pretty sure it's 32).

You'll get about 4000 feet of elevation if you fire straight up. That's an estimate and you are firing straight up because I just really don't feel like playing with curves right now. I only do anything between algebra and quantum physics if if I have to.

Anyway, 4000ft up. 32ft/s^2. It has the capacity to kill or maim, just like a .22.

The .22 will be coming down slower though, as it will likely be tumbling by that time and increasing drag by doing so. The round ball really doesn't care if it's tumbling.

Josh

 

[hawk]

For anyone having useful information to share, I'm trying to find out if shooting at tree top squirrels with a .32 poses a danger to other hunters in the area



why not use a shot gun then?

 

[Norinco]

Which is when you use the velocity squared times the coefficient to determine drag force.

 

[Pete Gaimari]

For anyone having useful information to share, I'm trying to find out if shooting at tree top squirrels with a .32 poses a danger to other hunters in the area



why not use a shot gun then?

I always thought hunting squirrels in trees was dangerous. I see i'm not alone with those thoughts.

 

[GBG]

Maybe not as dangerous as I believed if a 45grn .310RB falls back at 180fps. I've got a slingshot that will shoot a 160grn marble at 230fps and its not lethal to humans. BTW, I stopped shooting at squirrls with 22LRs 30 years ago and haven't used shotguns in 15.

 

[hanshi]

Something to keep in mind; unless a projectile is fired absolutely, positively straight up - 180 degrees opposite the pull of gravity, it will not obey the physics of a free falling object. If the rifle is canted, even a little - the closer the declination to the horizontal the more danger - the ball will conform to the physics of ballistics. In other words the ball's potential danger comes not from the speed of free fall but from remaining velocity of the shot.

 

[GBG]

True, wish I could find a ballistics table for RBs fired at steep angles. I'd like to know for sure how big the "drop zones" are and how fast the balls hit. Might feel safe enough to try small bores and scatter guns again.

 

[Norinco]

But the downwards component of the velocity will straight up be free fall plus air resistance. Not to mention that at some steep angles, the air resistance will take away almost all of the projectile's lateral speed, so it will fall straight down.

A 150 grain .30/06 bullet's terminal velocity is about 300 FPS, with about 30 ft-lb of energy. It was determined to be nonlethal, but still dangerous http://www.loadammo.com/Topics/March01.htm

I'm assuming the .30/06 bullet came back down tumbling. Whatever the .31 cal round ball does, I'm guessing it can't have more than 15 ft-lb of energy.

 

[GBG]

The Army report on the test you mention says the 150grn spitzers were falling Base-First and put 1/16" dents in soft pine boards. People have been shooting RBs up for 500+ years and I haven't found one record of measuring how fast they fall back down...yet.

 

[Norinco]

In that case, the cross sectional area for both projectiles would be the same as they fell. The .31 round ball wouldn't be very fast as it fell, but it will still hurt.

There's probably never been a study of how fast round balls fall back to earth because no one cares enough to do them.