Sorry I can't help you on this other than to say you might just tear it down enough to remove the spring, measure it, and see or EM ARH (Maccarri) with what you have and see if he has a spring that is close. Does the rofle have a synthetic seal, or a leather seal?!? If it's leather, you may just need to drop a bit of silicone in the port to moisten the seal if it has dried out some. I think you can use kneats foot oil for the same application. Hopefully the Chinese Guru's will chime in on this one. Best of Luck, tjk