I've never heard that one before. Actually, with a lot of use, you will have to change the piston seal and re-grease the spring and you're back where you were. I have owned Feinwerkbau, HW, Crossman, Benjamin, and I have never had one get quieter. That just doesn't happen. Tuners use to put a kind of tar on the spring that could really quiet one up, but the sound went up from application time, not down. The good guns are pretty quiet already, especially if they are a sub-12fpe gun. Anyway, if you are set on getting a mod for yours a long slip-on style would be the way to go. Too expensive to do anything else. A good price for getting your barrel threaded is around $150 and then you'd still have to purchase a mod, so now you are at the same, or more, than the original price of the gun. Honestly, hand your gun to somebody else to shoot and walk 25y away and listen. It sounds a lot less to what you are shooting at, then what you hear while shooting it. In the long run, if you are a springer guy, get a shrouded British or German airgun, but don't throw your money away trying to make your gun something it isn't. Just trying to save you from learning the hard way, like the rest of us, but do what makes you happy, and good luck