Atleast you're son got to put 50 rounds through his. I just purchased my Sig Sauer P250,(NEW). I took it home and attempted to break it down to clean the packaging grease before shooting it, the take down lever also was seized, and when I finally took the slide off,the plastic tip on the end of the guide rod broke clean off, ejecting the spring. I have a Ruger 380 lcp that has the same style barrel and guide rod, but it's steel. I don't know why in the world would they would make a critical component of the gun, plastic. I read the instructions carefully, the take down lever was stuck no matter what position the slide was in. And after reading your post, I don't belive I made an error. I will be calling Sig today and asking for several replacements shipped to me and will recommend they take a second look at the guide rod.