Bullet temp in flight

[Doom2]

I'm guessing opening pandoras box here but would bullet shape and construction also have drastic affects on this. A solid bullet vs C&C that is made with more than one alloy with different heating and tranfer rates. Would think that a solid such as Hammer would have either an advantage or disadvantage delending on which direction the pendulum swings on that. I would think advantage??

The answer is yes. In fact the finer the tip is the faster it should heat. Most metals in use for bullets do not have structural issues from heating due to there short flight time. True supersonic design aircraft have to make provisions for dissipating heat that it encounters. A more blunt nose will have more drag but the the shock wave tends to be further away from the nose.

 

[Rflshootr]

All I know is that it isn't hot enough to catch a paper target on fire at 25 yards or cauterize the wound of any animal that I've ever shot. Other than that, I'm clueless.

 

[Jonoton]

Oh how I wish I was interested in high performance projo aerodynamics during undergrad aero engineering
I had ready access to supersonic wind tunnels and a favorite professor developing temperature color shift coatings.

 

[RockyMtnMT]

Oh how I wish I was interested in high performance projo aerodynamics during undergrad aero engineering
I had ready access to supersonic wind tunnels and a favorite professor developing temperature color shift coatings.

I wish you would have too!

 

[rickjoty]

I had my doubts about the high temp tips but I have had an interesting personal situation where Barnes TSX bullets were more accurate than the TTSX. It made me wonder about the tips becoming deformed then Hornaday comes out with their high temp tip. I have not tried them as I have drifted away from shooting the last few years. I'm interested to see where this goes. Any words from Barnes???

 

[chutinlead]

Hornady's podcast went over that topic and they had the ballistician on that was instrumental in the design of the ELD-M/ELD-X. If I remember correctly, it wasn't till they went over 0.3 G7 that they began to see erratic behavior of bullets and even then it wasn't till after 400-500yds. They never would have seen it if not for big Doppler radar.

The higher BC kept higher speed up for longer and more time in flight at longer distances to melt tips.

Edit - I believe it was this one:

 

[DMP25-06]

Well , I am NOT an aeronautical engineer , and I have no means to test bullets to determine accurate results , so I will use a comparison of a KNOWN object being tested as a comparison , that seems logical to me .
However , people often accuse me of having twisted logic .

The SR-71 Spy plane had a published top speed of 2193 MPH which equals 3216.4 FPS .
That speed was not instantly achieved , it was attained after several minutes of flight .
According to Lockheed Aircraft , designer and builder of SR-71 , the temperature of the nose of the airplane at 2193 MPH was approximately 800*F , and at the windshield it was 600*F .
According to documents that I looked-up , this was not due to friction of airflow over surface of the airplane , but instead was due to compression of the air molecules in front of the aircraft at that speed .

So , in my twisted logic , I think that the 800*F temperature would be the highest possible temperature that a bullet might attain at 3216 FPS velocity , and that would be after several seconds of flight time at a CONSTANT 3216 FPS , not a constantly decelerating curve of velocity .

In my opinion , the original Ballistic Tip , the Sirrocco tipped bullet , the A-Max , and the Tipped Match King bullets had no problems with plastic tip deformation , and the "New ELD tip" was strictly marketing .

Years ago , while hunting in the mountains of Colorado , I found a .30 caliber 165 gr. spitzer-style bullet , with exposed lead-tip , that had been fired from a rifle , probably .30-06 or .308 , that had fallen to earth without striking any object , other than the earth when it landed .
The lead tip was not melted , only scuffed , and one side of the copper jacket was scuffed and somewhat flattened from hitting the dirt and skidding .
That lead tip had not melted , so it makes me question how hot it got , since lead has a melting point of 621.5*F .

 

[yorke-1]

I'm sure there's a quantifiable difference between aluminum and plastic tips on bullets in regards to resisting heat related deformation, I just don't know if there's a practical difference.

I think Hammer should use a custom colored plastic tip just to be different. The aluminum, black, red, and green tips are boring. You need to use one that matches whichever Pantone color of orange you're using in your logo. Then you get points for style and function!

 

[RockyMtnMT]

Someone needs to figure out how to catch a bullet without messing it up, after it has flown a couple thousand yards. That should settle it.

 

[Doom2]

Well , I am NOT an aeronautical engineer , and I have no means to test bullets to determine accurate results , so I will use a comparison of a KNOWN object being tested as a comparison , that seems logical to me .
However , people often accuse me of having twisted logic .

The SR-71 Spy plane had a published top speed of 2193 MPH which equals 3216.4 FPS .
That speed was not instantly achieved , it was attained after several minutes of flight .
According to Lockheed Aircraft , designer and builder of SR-71 , the temperature of the nose of the airplane at 2193 MPH was approximately 800*F , and at the windshield it was 600*F .
According to documents that I looked-up , this was not due to friction of airflow over surface of the airplane , but instead was due to compression of the air molecules in front of the aircraft at that speed .

So , in my twisted logic , I think that the 800*F temperature would be the highest possible temperature that a bullet might attain at 3216 FPS velocity , and that would be after several seconds of flight time at a CONSTANT 3216 FPS , not a constantly decelerating curve of velocity .

In my opinion , the original Ballistic Tip , the Sirrocco tipped bullet , the A-Max , and the Tipped Match King bullets had no problems with plastic tip deformation , and the "New ELD tip" was strictly marketing .

Years ago , while hunting in the mountains of Colorado , I found a .30 caliber 165 gr. spitzer-style bullet , with exposed lead-tip , that had been fired from a rifle , probably .30-06 or .308 , that had fallen to earth without striking any object , other than the earth when it landed .
The lead tip was not melted , only scuffed , and one side of the copper jacket was scuffed and somewhat flattened from hitting the dirt and skidding .
That lead tip had not melted , so it makes me question how hot it got , since lead has a melting point of 621.5*F .

The SR-71 did not achieve Mach 3 until at high altitudes where the ambient temperature is much lower than 70F. In addition the SR-71 had fluid cooling of the surfaces using its jet fuel.

As to the recovered bullet it is heaviest part of the bullet and heat is transferred from the tip to the body via conduction. Unlike a metal with a fairly high heat transfer coefficient the plastic tip does not transfer heat nearly as fast from it's surface. You do not know how long that bullet flew and was exposed to the higher temperature.

As to whether Hornady actually saw an issue or not I do not know. I do know that the potential exists for this to happen with low temperature polymer.

 

[Gorill@]

I know at 450 knots, the cockpit of a F-16 canopy is hot enough to burn the **** out of bare fingers (Ops tested!)

 

[Gorill@]

The SR-71 did not achieve Mach 3 until at high altitudes where the ambient temperature is much lower than 70F. In addition the SR-71 had fluid cooling of the surfaces using its jet fuel.

As to the recovered bullet it is heaviest part of the bullet and heat is transferred from the tip to the body via conduction. Unlike a metal with a fairly high heat transfer coefficient the plastic tip does not transfer heat nearly as fast from it's surface. You do not know how long that bullet flew and was exposed to the higher temperature.

As to whether Hornady actually saw an issue or not I do not know. I do know that the potential exists for this to happen with low temperature polymer.

Infrared can easily record inflight temps. Obtw, the SR would stretch 8 inches due to parasitic drag. Skin temperature IS a limiting factor in high performance aircraft. Ergo, that bullet will get hot, fast, at any high speed.

 

[orkan]

The heat the air puts on a bullet in flight, is nowhere near the heat the friction in the barrel puts on it.

 

[RockyMtnMT]

Infrared can easily record inflight temps. Obtw, the SR would stretch 8 inches due to parasitic drag. Skin temperature IS a limiting factor in high performance aircraft. Ergo, that bullet will get hot, fast, at any high speed.

Exactly. That is the question. How hot in sub 2 seconds of flight with constantly degrading velocity?

It sounds like the hottest it could possibly be is 900*f? How hot does a bullet get if it is introduced to that temp for 1 second? I'm thinking 900* is to much?