I have often wondered about the polymer tipped bullets from various manufactures. I have read of people seeing wisps of lead on paper targets that apparently came from lead tipped bullets that melted in flight. If the heat at the tip of a bullet can melt lead then the type of plastic used for bullet tips needs some serious consideration. But, I figured the bullet manufacturers knew a lot more about this than I did and had it all under control.
It turns out this was not the case:
the Hornady engineers observed a convex hump form when charting the new bullet’s drag. The hump was relatively small and usually occurred within the first 100 to 200 yards of flight, and following the hump the drag curve returned to its expected concave climb and drop. The irregularity may have been small and short-lived, but the shift from concave to convex, and back again, seen on the Cd vs. Mach Number graphs could only have one explanation: The bullet itself was changing shape in flight.
It did not take long for the Hornady team to realize it was not the whole bullet changing shape, only the non-metal component—the polymer tip.
The solution, of course, was to find a new polymer:
New polymers were tried and tested, and one was found that met the company’s criteria. With the new material, the Heat Shield Tip was born. Molded as precisely and consistently as previous polymer tips, the Heat Shield Tip boasts glass transition and melting points hundreds of degrees greater than the previous generation’s—475° F and more than 700° F, respectively.
This resulted in higher ballistic coefficients (BCs) which translates into less windage and drop.
My favorite bullet for .30 caliber long range shooting has been the Berger 210 grain VLD bullet. It has a G1 BC of .621. The Hornady 30 Cal .308 208 gr ELD™ Match bullet has a BC of 0.670. From 700 yards away with a .300 Win Mag with Boomershoot conditions this increases the velocity by 60 fps and decreases the drop by 2.6 inches. This isn’t enough of a difference to throw away my existing bullets but I think this is what I’m probably going to replace them with.