I do not currently own a Glock and have read all the GT 9mm vs. .40 debate threads trying to decide which to buy. I am not a LEO and I do not use a gun in my job. In addition to the standard personal protection reasons for owning a handgun, I am interested in the shooting sport of IDPA/IPSC. I have boiled my Glock model choices down to a G17 or a G22. I have rented and shot both models and will definitely need a lot of practice with whatever I finally purchase. I am trying to decide which model would be better for IDPA/IPSC and was wondering what everyone else is using. My research shows me there isn't a predominance of one caliber over the other. I had one guy tell me that some of the targets put up a fight against 9mm and that the .40 is the better of the two calibers. I don't want to start another 9mm vs. .40 debate; I just want to know what caliber you use for IDPA/IPSC and why. Also, please indicate what weight round you use in the caliber you use.