All you have to do is change the barrel. I used a Federal barrel and had no mechanical problem. Accuracy was acceptable, not great. I wish I had used a Jarvis barrel.
You get less percieved recoil when compared to 180 gr .40 S&W, about the same with 155. You do get LOTS more flame and noise. What you also get is a lot more expense for the ammo. My advise is to get the 357 Sig barrel because you can say you did. Then, put it away and shoot 155 gr 40s.