Does slightly deformed tip of bullet affect ballistics under 100 yards?

Would symmetrically sharpening the tip of a bullet make any difference in long range accuracy?
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I don't know, but my guess would be "not enough to matter". Look at the long range match bullets today, all are very, very pointed, but none comes to a needle sharp tip.

I would also think that if you "sharpened" the bullet enough to change the BC that would make a difference in long distance flight, though perhaps not in the accuracy (group size) necessarily.
 
44 AMP said:
I would also think that if you "sharpened" the bullet enough to change the BC that would make a difference in long distance flight...
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An interesting test of this would not be that difficult to do. Heck even I could do it. All the known data and facts seem to point to the assumption that it would make no difference, but would be interesting to try anyway. Sharpening 5 or 10 bullet points in my shop to exact needle points would only take a few minutes on the metal lathe. The bottom line however, is I would think that if a needle point sharpened bullet would indeed make a difference, the long range match shooters would already be doing it. Thus... a moot point.
 
At ordinary distance it makes no difference. One of the 2 most accurate billets tried in my old savage 99 243 is the Speer 100 grain boat tail soft point (not the hot cor). It’s a very soft bullet, some of them look “smeared” like the exposed lead got roughed up and the tip is visibly shoved to the side. Still accurate. As distance grows, this would definitely be a problem. Blowing up milk jugs out to 300 yards, no discernable effect. As had been said, the base is more important if not concentric. All 1000 yard records have been made with boat tails, and pretty much all 100 yard records are made with flat base bullets. At distance the aerodynamic efficiency of the boat tail becomes more important than the greater inherent accuracy of flat base bullets. A flat base is less sensitive to imperfections in the crown of the muzzle, a worn throat, rough rifling, seating depth, pretty much everything. It’s not that they fly better, they don’t, it’s that less can go wrong with them.
 
First off, with a bullet, it is not only pushing through the air, but also spinning rapidly on its axis. Mass, inertia, torque, and other factors are in play. Bullets are essentially pointed rods thick at the back, thinner at the front. So a tiny change that does actually unbalance the front is over-ridden by the still balanced stability of the more massive rear section.

Anything less than a perfectly balanced nose will "wobble" it's something that could be calculated, math says it must exist, but the effect of that tiny wobble is (usually) hidden /overwhelmed by other factors, so there is seldom any effect on accuracy we can see.

An "unbalanced" bullet base, on the other hand, has a great effect. It is the greatest mass of the bullet, so if the weight is lopsided (not "true" with the spin axis) the bullet won't fly true, either.
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This is all correct.

Two things to consider, or so...

That slightly deformed tip actually takes only the tiniest bit of material and puts it off balance, right there at the axis of rotation. With the spin of that massive bullet, the thing is going to be stabilized based on all the rest of the lead. That little bit of skewed weight at the end of the axis can't possibly upset the stability of the rest of that mass. Not that it would really matter, as shown by the football, even if the nose started to rotate the body (center of the mass) would still remain stable (in relation to itself) in space without being affected.

While some people would think that friction would affect the bullet adversely, that air would push it aside, much like the spoiler on a car, once again, we have so little deviation that could be caused by the friction that it wouldn't be able to push the bullet off of axis. Again, pushing it off of axis would not result in the bullet taking another path, it would just cause the bullet to "wobble". Since it is also rotating, it also has to be pointed out that if the pressure or imbalance is on the 'outside' of the rotation, it's going to just guide that deviation back to center. Unless the damage causes deviation outward from the axis, there won't even be a reason for the thing to destabilize from the axis, it will self correct.

As was said, it has been tested, and casual testing showed no deviations. If you set up scientific conditions and tested it in the most extreme distances, there still may not be any deviation that would show when compared to bullets with perfect points.

As we have read, yes, damaging the base where the mass is located can cause the bullet to have problems. First, a chunk of missing base material causes the bullet to leave the bore with a 'poof' on one side, causing a tiny bit of instability. Friction at outer edge of the base can cause the heavier base to destabilize a bit. with both wind drag and a weight being off center of the axis, any deviation at the edge and towards the center of the mass will be more inclined to push the axis off.

Look at someone whacking a golf ball. See how the dimples make them go on wide, arching flights? The dimples on the bottom are resisting the air that they are flying into. The dimples at the top are not having to resist that pressure. The dimples at the bottom actually function like a wedge, or ramp, as the dimples are forced through the air, pressure against the dimples on the bottom push on the center axis of the ball. This will cause the ball to climb if the ball is rotating backwards.

Regardless of what direction the ball is actually flying, it will follow a straight (mostly) line perpendicular to the rotating access, just like a gyroscope.

Let me be the first to assure you that whacking a bullet with a golf club isn't going to answer any questions. It will just waste a lot of bullets.
 
If I remember correctly, handgun rounds spin 70,000 to 90,000 rpm. Rifle rounds are 200,000 to 250,000 rpm. But for the distance being mentioned, not very far to affect accuracy. Now for an out of balance bullet at 1,000 yards, I'll bet it is buzzing and tumbling by then.
 
hmmm, let's see...

take a rifle bullet at 3,000fps...
and, to make it easy lets say 1 in 12" twist..
so that's 1 turn per foot, and 3,000 feet per second x 60 seconds in a minute..

I get 180,000 rpm, rotational speed

Somebody else can tell us how that compares with a power drill, or the compressor vanes in a turbocharger..or jet engine...

Sounds really fast, to me, but is it?
 
It is pretty high rpm,but the answer s right in front of us. Every thing slows down,but one turn in 12 inches ? Is one turn in 12 inches. Or 3 per yard....

Sort of dampers the theory of the spinning bullet buzz sawing the insides of a critter.If nothing slowed down,the bullet would make about 1 1/4 turns passing through a deer.
 
To expand on my comments, I'm trying to find the photos that I've seen over the years of bullets in flight showing how the "atmosphere" for lack of a better word, flows around a bullet.

Essentially, a high velocity bullet's nose is in a fairly static bubble as it flies, meaning that it really has very little effect on the bullet's path.

The best photos that I've found are on the Wikipedia page on external ballistics.

This one, in particular, shows both the bow shock wave and the trailing turbulence path from the bullet's base.

https://en.wikipedia.org/wiki/Exter...w_shock_waves_around_a_brass_bullet,_1888.jpg


In the images I've seen where bullet bases are imperfect, the trailing turbulence path is a LOT more confused and decidedly not symmetrical.
 
I was always pretty good at math. By using my skills with physics and other disciplines, I can say with absolute confidence that a bullet that was fired from a rifle with a 1;12 twist, travelling at pretty much any realistic velocity will rotate 100 times at 100 feet, and 300 times at 300 feet.

The information shared here has been great.

To address the buzz saw effect, almost anyone here has seen gel tests. Myself, I've never seen any one of them with a buzz saw, whenever I have seen evidence of rotation, it's been one rotation in the block, just as it would be in flight.

But we are talking about accuracy, and just offhand, I think that mike has provided the best information as well as links to pages that can confirm it and provide further information.
 
Something to think about. Year's ago Speer brought out the mag tip bullet. The idea was that the tip of a bullet melts off soon in flight. They had a high speed photo of it happening to sell their idea. If that is true then banged up bullet's don't hurt a thing. I think we can go even farther back than the mag tip and see the Rem core lock.Not much exposed tip on it either and it's a great bullet. On the other hand seem's I read somewhere that the plastic tip protect's the tip of the bullet. Probably does but better at starting opening I would think. Not sure the tip below the jacket need's protecting.
 
The only part of the bullet that matters is the base. If the base is damaged, in any way, the gases go in odd directions. That throws accuracy off.
Makes no difference what the point looks like. Think in terms or the plethora of point shapes. All of 'em are accurate.
 
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