Everyone knows the expression “hot lead”, meaning (flying) bullets. But how hot are they? Does the temperature of a bullet rise substantially upon firing? How hot are they after flying 30 feet? 100 feet? 200 yards? Bullets vary wildly in size, shape, construction etc., as do the cartidge loads that drive them, so there’s no one answer, but I’ll appreciate any hard data on the subject.

I don’t have any numbers for you, but consider that the casing is very hot after a fraction of a second of exposure to the hot gasses and pressures. The bullet experiences the heat of the gasses, pressure that pushes it out the barrel, and friction for the length of the barrel. Cases are often too hot to hold right after firing. I assume the projectile would be similarly warm.

Also when they collide with anything solid - a wall for instance, they deform and the heat of deformation can melt them, depending on their residual velocity.

Maybe they feel like they’re hot, even if they aren’t.

Never been shot… (Yay, me!)

I know from testing done in 1903 by Louis LaGarde (Poisoned Wounds by the Implements of Warfare, Journal of the American Medical Association, 4/11/1903) that bullets don’t heat up enough to sterilize them. As for exact temperatures, dunno.

Well, the bullet itself presumably has a lot more mass to it than the casing, since the casing is made from thin brass, and the bullet, is, well, a wad of lead, which itself is pretty dense compared to brass.

How would you even measure this? Fire directly into a block of ballistic gel and point one of those thermometer guns down the entry wound?

If the bullets inside are hot, why do I feel so cold?

This link (http://www.rangerats.org/bullet.html), now broken but still comes up on Google, says 513^F. Can’t get more details from there than that.

Paper patching per Quigley, is not a Hollywood invention. You really can wrap the rear of a lead bullet in high rag content paper and not have it hot enough to burn up when it hits the air.

A slow rifle bullet is doing 1500 feet per second. A long barrel is maybe 24" long, so the bullet is exposed to the hot gasses for maybe 1/500 second, and only the base of the bullet is exposed. Thats 2 milliseconds…it would take a hell of a temperature difference to move much heat through the base of the bullet in that time.

The paper patching mentioned above is done because when you try to push a lead bullet faster than around 1300 fps or so, the hot gasses start to blow past the bullet (gas cutting) and cause barrel leading and inaccuracy. One theory is that at these pressures/temperatures the surface of the lead melts. That would happen at 700F or so, but nobody thinks that the interior of the bullet heats noticably.

A lot of folks think it is not heat that does it. The bare lead limit seems to hover pretty well around the 1300 fps mentioned above, even with different bullet weights which implies different pressure and temperature of the gas behind it. Type of lubricant applied to the bullet can move the limit up or down some, so lots of people think it is purely a question of friction…a sort of speed limit for lead on steel where the lead starts to stick to the steel.

OTOH, you can also put a copper “hat” (gas check) on the very rear of the bullet, and stop the gas cutting…so much for the friction theory. Or not…maybe it is a combination of things.

Anyway, back to the OP: You could hit the bullet with an oxy-acetlyne torch for 2 milliseconds and not raise the temperature more than a couple degrees. “Hot lead” is just a figure of speech and has no basis in fact.