I have question 220 RN vs 240 SMK performance myself. Just today I was at the range doing some very unscientific testing. Shooting water soaked phone books.
As you can see neither expanded at 1050 fps. Although the SMK did penetrate about 4" deeper (approx 14" vs 10")
I have observed this lack of expansion in phone books before and in Easterm Whitetails I have shot. I am working with a bulletmaker right now to get some heavy 30 cal bullet's with light jackets in hopes of acheiving more expansion.
Pmc