Dave, there's plenty of your fellow member's that also have the B3 hehe let's see Gene, Jeff, John etc. etc.. If I missed someone sorry and yes I have three B3's, two are tuned close to 700fps and the last one is slowly getting tuned. You can turn them $20.00 shooter's into a fine little Airgun with the proper TLC. I didn't go with the JM spring, there's a kit for the "B"'s that has a spring for the B4 I think that will work just fine. Most of your effort should go into the action, spring guide and piston and of coarse the trigger. POLISH! and DEBUR is a factor and I know if you have any question's we all will jump in and help you get her tuned up. If you go back several post in the China Gate you will find ton's of info, we had a B3 CRAZE for awhile and there are some link's that will help you in your B adventure. Any question's , feel free to ask. Ed