I got my new M3 a couple weeks ago and I got it tuned and shooting really well using the JSB MK2's. I was really skeptical about it when I first placed the order but the more I have shot it, I really love it now as it is a very accurate rifle with the right tune. I think I can make it better though....I have been working on making a new barrel dampener system for it, I'm just waiting on some materials I ordered so I can get it finished and then I will start testing it. I've got a few years' experience with building benchrest rimfire rifles and making tuners etc. for them and a lot of the same can be applied to these air rifles. I don't want to say much right now about what I'm working on but I'm not a big fan of the tensioned barrel system as I have experimented with that before with not very good results. Hopefully in a couple weeks I'll be posting about this new system I'm working on.....Today, I did machine a new cocking handle for my M3 , I just wanted something a bit larger with more grip to it. I tried it out this evening and it works a lot better for me than the stock one did...I'll probably will just black it out like the original one...