I'm having a debate with some fellas over this question.
Does a hi-velocity rifle bullet shed its lead tip/point when fired? I'm talking spire point lead tip types not plastic tipped.
I seem to remember years ago that Speer showed hi-speed pics of this and explained that it was the reason for their flat tipped bullets.

I dont think they do at 3000-3500 fps velocitys.
I once thought that I worked up a load that did
because I thought i saw it happen in flight
but an old reloading master told me I was seeing a vapor trail.I could only see this on a hot day though.
As for the flat tips I was under the understanding that was there way of keeping the bullet from being deformed in the magazine upon firing them.Sort of a controlled deformation process or a manufacturing process i guess.

I suppose if the bullet was able to sustain a high enough velocity for long enough this could
happen I have seen the warings on some of the
varmit bullets as coming apart if you push them
to fast but i have not experianced it.

Short answer, NO
Long answer involves a lot of math, but if you subtract the 100yd energy from the muzzle energy you will get the amount of energy that is available to move through the air and heat the bullet.
Question, if the lead in the base of a partition dosn't melt from being exposed to the burning powder, why would the tip melt from air friction?
There is a condition where a thin jackett bullet is spun at a excessive rpm (say a 35 or 40 gr "Hornet" bullet being fired from a fast twist 220 Swift at max+ pressures) that will cause the jacket to rupture and the bullet to disintagrate, but that is a completly different thing (IE centrifigal force being greater than the mechanical strength of the material)

Tailgunner nailed it, case closed.

quote:

Originally posted by Tailgunner:
Short answer, NO
Long answer involves a lot of math, but if you subtract the 100yd energy from the muzzle energy you will get the amount of energy that is available to move through the air and heat the bullet....

I kind of agree with that.

But if you think about it, there are two types of energy in the discussion and they are "somewhat" in inverse proportions during the bullets flight.

You have the energy mentioned above which is at it's peak when it leaves the muzzle and begins degrading as the bullet moves forward.

Then you have the air friction energy created by the bullet drag which begins at nearly zero as the bullet leaves the muzzle. It then increases for awhile, levels off and begins decreasing due to the cooling effect of the air as it goes subsonic.
---

Part of this might be a bit easier to understand if you think of passing your hand through a burning candle. If you go quickly enough, your hand won't realize it was subjected to the available energy because the duration the energy had to transmit itself was so short. Increase the time your hand spends over the flame though, and the energy does transfer. Just run your hand through the flame slower "upside-down" and you will see the hair get singed off. And even slower will allow the transfer of energy to the point that it creates a burn.

And in this example, the "available energy" is not changing. Where, if you "slow" the bullet, there is less available energy, so the above example requires a slight bit of physics (or imagination) to understand when applied to a bullet.

Sounds like is a myth then, thanx fellas.

Once again, Tailgunner nailed it. If you would like to see some bullets come apart from excessive RPM, it is easy to accomplish.

Step 1: Purchase some 30 cal Speer 110 gr Varminter bullets.

Step 2: load them in a 30-06 case to 3300 to 3500 fps using data from Hornady #3 for the 30 cal 110 gr spire point.

One of my early adventures in reloading was this very mistake. It caused my Win 670 30-06 to function much as a shotgun. Reducing the powder charge to give a velocity in the range the bullet was built for restored rifle function to my Winchester.

Idaho...
Hah.. that brings back fond memorys you shoulda seen the muzzle flash from those BLC2 loads I cooked up for it in my ,308 win, they were as big as a basketball! As you stated tho the accuracy was not as good as could be hoped. LOL!

Westcoaster,

I was not very clear in my last post. Poor accuracy is not what I meant when I said "shotgun function". These bullets were actually disentegrating, either in the barrel or near the muzzle. Each shot would leave as many as a dozen holes in a paper target twenty yds from the muzzle.