… I thought the idea was to have the biggest frontal area possible to transfer the most trauma. Hence the pancake wouldn't be a bad thing.
I've often wondered how many shots the various bullet companys fired to get the few that they show pictures of.
A 60g .224” bullet and a standard 8-1/2”x11” piece of paper weigh about the same. Which would you rather be shot with – the pointy end of a stabilized FMJ .224” bullet (minimum expansion) or the flat side of the paper (maximum expansion) at the same velocity? I’d take the paper! As with many things in life, more (in this case, bullet expansion) is not always better.
The trick, as far as I’m concerned, is to obtain a good BALANCE. Good expansion but not too much. I’ve seen pictures of pancaked bullets that had almost no shank left and resulting sectional density approaching that of a flyswatter. The remains of a .224” bullet is sitting on my desk as I write. It successfully achieved maximum expansion, measuring over .9” in a couple different directions. This bullet has NO shank left and consists of the jacket with a thin layer of lead. This particular bullet hit steel at 200 yards, but its indicative of what I call 'over expansion'. Other .224 bullets that expanded less performed much better against the steel, forming craters instead of a splat mark. Here’s a pic:
Pretty awesome expansion but not much penetration – and that’s the tradeoff. Rapid and/or excessive expansion limit penetration. That’s why I prefer bullets that have some mechanism for positively limiting expansion – such as the crossmember in the Partition and A-Frame and solid shanks in the North Fork, Trophy Bonded, TSX/TTSX/MRX, and so on.
How many bullets do the manufacturers shoot to get pretty pictures? I don’t know, but I’m sure they have a lot of test bullets to choose from. Here are a few of mine, all recovered from water jugs.
Left to right, Speer 300g Uni-Cor .458", Speer 350g FP .458", North Fork 350g .458", Cast Performance 460g WFNGC .458", Hornady 220g FP .375", Barnes 180g MRX .308"
Crappy picture, but that's life.