Lead core bullets at Mach 4 and above information???

[Tommie]

Several folks have mentioned that they are shooting polymer tipped bullets at this higher end of the spectrum. I would like to put out a warning to those who are to be VERY careful with them. Unless you have a special coating that I do not know about yet you have to be at or very near the tip melt out range.
If this happens at the wrong time in the barrel things will get very exciting very quickly. It is very dangerous to have this happen at our near the crown when the separation occurs.

Many barrels will not handle the violent separation. Please be careful!

As always stay on target,

Carl C.
Extreme Accuracy

www.14caliber.com

I understood the tip melting issue happens in flight due to air friction. At least that’s what Hornady published a few years back. Your information suggests otherwise. What is causing the tip to melt during acceleration in the barrel?

 

[extremeaccuracy]

Tommie, I’m assuming the tip melting issue you’re referring to is what we call tip degradation. (Please correct me if I’m wrong.) With tip degradation the tip is slowly melted away during flight from the heat generated from air resistance during its travel down range. This often happens even at much, much lower bullet speeds and can be a problem over longer distances. Some examples below:


It can be reduced to some extent by using different additives to the plastics and with some coatings.

Tip melt outs on the other hand, are a situation that occurs when the bullets are accelerated and spun at a very high speeds. The materials cannot handle the violent acceleration, high induced spin rate and heavy heat load placed on them during acceleration down the barrel. While this feature is often useful at the end of the bullets travel to induce good bullet separation (from rapid deceleration) it is not wanted and dangerous during acceleration in the bore. It can be very dangerous if it happens right at the crown.

As always stay on target,
Carl C.

Extreme Accuracy
www.14caliber.com