I called Glock today regarding a replacement recoil spring assembly for my G20SF. The employee on the phone asked me what was wrong with the current RSA, and I told him it felt weak, and was possibly causing malfunctions. He asked me how many rounds were through the gun and I told him about 1000. He then asked my weapon serial number, and I gave him what I thought it to be off the top of my head. He took my name and information down, and said no problem I will send you one. Good customer service!