precession

[wszumera]

I got a question concerning how a round ball rotates in flight. I know the ball is spinning from the rifling but if I remember my high school physics, it would seem as the ball falls the ball is going to rotate at right angles to the fall direction.

So the big question I got is. If you load with the sprue down, does the sprue make it around to the front in 90 to 100 yards?

Thanks,

Clutch

 

[Blivetmaker]

Nope. It'll travel downrange spinning like a football. The sprue will remain pointed rearward.
Gravity's acceleration toward the earth's center will cause the ball to drop at a steadily increasing rate, but this vector won't affect either it's downrange movement or it's rotation around it's own axis.

 

[LRB]

Your best accuracy will be sprue up, as it is much easier to load centered. Better yet, is to have no sprue.

 

[jimeckersley]

Your best accuracy will be sprue up, as it is much easier to load centered. Better yet, is to have no sprue.

When you say, "Better yet, is to have no sprue," do you mean use a swaged, rather than cast ball? Or do you mean remove the sprue?

 

[TANSTAAFL]

That pristine round ball so many seek? Well, after the loading/ramming process and the soft lead deforming under firing pressure, that ball leaving the muzzle bears little resemblance to the ball you put into the muzzle. In short, it ain't round no more.

 

[RedFeather]

Don't know about round balls but a torpedo will drift right or left along it's path due to the earth's rotation - "gyroscopic precession". That's why the old WWII fish had gyroscopes in them to counteract this effect. You had to set it for the lattitudes you were sailing in. And vice-versa if you were below the equator. I sometimes wonder if there isn't that effect of a bullet, but I think the speed and distance must make it a very neglible one, if any.

RedFeather

 

[mike alexandre]

I agree with your statement but its just as well that Clutch didnt ask the question about smooth bores or we'd have to bring Mr Robins info into the answer?

 

[Zonie]

RedFeather: I think the gyroscopic precession applies to the roundball but it's effect is minimal.
How many torpedos get to their target in less than half a second? :grin: :grin:

Just funnin wit ye.

 

[greenneck]

I believe what you are talking about is the Coriolis force, making every moving object deviate from a straight path slightly to the right on the Northern hemishere and to the left down South. That force is always there on this rotating Earth, but way too small to make any difference to us ML shooters, unless you are using a micrometer to measure your group sizes. :rotf:

However, you can see the effects of the Coriolis force very clearly in most every weather report.

Steve

 

[RedFeather]

You can see it every day. Just watch after you flush! :grin: