as far as simplify, I tend to read it a little diffrently..
yes while it is nice to have the ability to swap mags, I'm not going to let that be the deciding factor..
I look at it not by actions, but instead by calibers...
in case of calibers that are a little diffrent, well.as long as the projectile can be used in both its not a big issue to me.. 357 vs 38 ,222 vs 223, 243 vs 244 etc..
I don't have a 40, but if I did I'd also look for 10mm as projectiles can be used in both..