I had the same issue with wolf recoil springs getting caught under the guide rod. I don't know how the gun kept functioning with the recoil spring caught under the guide rod. When the recoil spring got caught under the guide rod it took around 50 rounds for me to figure out what was happening. I couldn't empty a magazine without the gun jamming. Yet his gun only malfunctioned once in 4,122 rounds despite the issue with the recoil spring.