My son and I were at my range both firing our Kimber 45 1911s , when we heard what sounded like a dud shot ! FIRING at 25 feet , we saw no holes in the paper target ? My son pulled the slide back and saw a 40 s&w round fired in the gun but the caseing was stuck like concrete. With a brass cleaning rod we pushed it out , the case was split from mouth to the base but there was no damage to the barrel! Moral here is to always check your rounds ,if you fire more than one caliber pistol. I don't know if other tight chamber pistols will fire a 40 cal. or not , but always check your mags!