OK, I purchased my first 15-22 at the end of March. It had serial Dtx4*** and it did not come with Blue Springs. My boy and i have put over 2000 rounds with only 2 FtE'S. I think there was not enough powder to push back the bolt all the way and they got stuck on there way out. Other then that flawless! We have had so much fun we just purchased a secong 15-22. We purchased it last night a Big5 in Cali. I opened it up and it had the Blue Springs. The funny thing is that the serial number id Dtx2***. I have only seen the Blue Springs on serial numbers that were after my first one the had the higher serial number. ANY IDEAS?????