New owner in CA with problems

I just got this great looking gun. i Also bought 4 more 10rd magazines. Almost every time I shoot the round before last gets jammed. It does not matter if I put 10 or 5. I cleaned the bun before going to the range but can't figure out why it jams. The jammed bullet comes out slightly deformed. To me it looks like magazine problem. Did anybody resolve it?

Send it back. I have had issues and they fixed them. Runs flawless now.

Its a mag issue. The feeding angle of the gets more vertical with 2 left in the 10rd mags. Check this form for the g21 10rd mag mod also