Internal spring failed after 100 rounds - DPM Heckler & Koch G3 Standard Recoil Buffer Assembly

Bought it for my PTR to reduce felt recoil but the internal spring in the buffer failed after some 100 rounds. On the surface it looks like a really well built buffer, especially compared to other similar ones on the market. I noitced the failure after seeing roller dents on my PTR. After investigating and taking the buffer out and giving a light shake I could hear the spring rattling inside the buffer and thus obvious the buffer failed. shame... also the washer for the factory stock screw was missing.