I've been using the 100 grain Mags for 6 years or so but today I came across something weird. Look at the difference in the picture...see the ferrule area?? One has a more pronounced slope than the other?
I'd bet the top one is the newer version. They both look deadly to me and I doubt if there will be any change in arrow flight with the difference in the slope. I'd be interested to see the blades and the slope on the cutting surface of the old blades vs new blades.