I bought a P229, it can't with a 40sw and 357 sig barrel. I only bought a box of Speed Lawman TMJ 125 ammo, just to experience shooting the 357. I shot 2 magazines and also the same amount in 40. The 357 seemed to have noticably less recoil and I was able to make tighter groups. I didn't notice any difference in noise level, but I'm sure if I had been observing instead of shooting, I probably could hear a difference. It's a very nice round to shoot, though much snappier than a standard 9mm. More in par with a light blow back 380 pistol. If you own a 40, I recommend getting a 357 barrel.