I received a Sig 250C for Christmas. I shot it for the first time last night. After shooting all in the magazine (slide locked back) I set the gun down, loaded the magazine, and when I put the magazine in and hit the bottom of it to seat the magazine. The slide slamed shut. I did not hit the slide release button or did I have my hand near it. It did it every time I hit the magazine rather hard. Is the ok or is there a problem with the gun. Thank you