Jeff:
Indeed the rage does use an o-ring. The practice tip they supply flies identical to the real thing! I have been shooting the 2 blade since they came out. I saw you were dissapointed in your blood trail with muzzys. Well let me tell ya when you hit a deer with a rage its unbelievable. I am a firm believer in them! I tell ya Jeff I will even send you some used one for you to try if you want? Just p.m. me your address. Shoot it and then get the replacement blades for them and you will be good. I think I got some extra o-rings too. Let me know! Tim