RE: 7mm rem mag
There is no such thing as "too fast to expand!" UNLESS the bullet is not designed to expand or if it is designed to expand on thougher game! Other than that, higher velocity, more expansion!
Thatsyour opinion....I have used lighter fast grains at close range and had PIN size holes i havent lost one yet, because even the pin size holes work when you put it in the kill zone but i beefed up from 130 grain to 150 grain and have shot them at 10 - 15 yards and had NICE holes....
Out past 50 yards the 130's work fine, but too close and they dont do enough damage for me..