I did find some things interesting while sanding all these bullets down. Hornady's tips including the Vmax and Amax can withstand more heat without melting than Sierra or Nosler tips. If Hornady's melting tip theory is correct, their bullets will likely maintain better Ballistic coefficients than the other polymer tip bullets.
The cross sections of this collection of bullets is pretty cool, but even though the bullets may look generally the same in design they are not at all the same. I believe that one of the biggest differences in all these bullets is the alloys that are used in their construction. After sanding these down it seems that the jackets and cores vary between manufacturers and even different bullets of the same manufacturer.
The Speer bullets are very soft inside and out and felt like they may be close to pure copper and lead. They were hard to hold (with pliers) without crushing them. The Sierra bullets were also somewhat soft and they clogged up the sand paper with their softer lead. Hornady seemed to have the hardest lead with almost no lead build up on the sand paper. The Barnes varmint grenade looks like solid copper but if you zoom in you can see the core is seperate from the jacket. The core is hard and was very easy to sand through with no clogging of the sand paper.
I will have to look into ways to test the core and jacket hardness to know for sure, but it does seem to be the main differentiator to this not very scientific approach at understanding bullet construction.
DH
