Pay VERY close attention to the oring on the striker. It may not look damaged, but all's it takes is a tiny nick in it, and you're out of business. Try replacing the striker oring. Whenever I play with a blowback gun I always make sure I have several spare striker orings on-hand. Your main striker drive spring may be worn out too.
Originally Posted by toasty414
I thought the same thing, so I lubed everything yesterday. It seemed to help a bit, meaning it rocked back and forth more times than it did unlubed, but it still doesn't catch back. I'll take another look at the orings but I'm fairly certain we already checked that out. And, the tanks were full- we tried a few different ones that worked great on other guns.