There was a guest (sure as hell not my guest) at our deer lease one year who said he was shooting a 300 RUM AI. He was claiming some astronomical velocity. I asked to see a piece of fired brass. He didn't have any. I asked what the handload specs were, he said he wasn't loading yet. I asked where all the velocity was coming from. He said something like when the powder starts burning it blows the case out to the vastly superior AI shape. Then the remaining powder burns so much better it gives the bullet that extra zing.
