Definitely ignore the % column...
I'm a little surprised he included that column at all...I don't want to get into the general methodology argument here (it would be the 5 millionth time that's been rehashed) -- but beyond that, there are two other problems.
First, he's made choices about what load to select the % for...but I'm not sure that the best loads have always been selected (could be wrong about that, it's been a while since I studied the M&S numbers).
Second, some of these loads are not going to do as well as the M&S numbers in short barrels. Example: I'll bet the .45 ACP % is for guns with 5" barrels; some loads that do very, very well in 5" .45 barrels do much less well in 3.5" barrels (the Fed 230 gr HS is an example).
There's a lot of good stuff on the chuckhawks website, so take this all FWIW.