[Masterjuggler98]

I just recently installed the ir-hop in my bar10 that's shooting about 550 too. I'm getting much better range and groupings than with my nineball bucking. I havn't fine tuned it yet because I havn't modified my hop arm yet. Going to soon though. You want the arm to provide an equal amount of pressure along the whole ir-hop and like cheese says, a longer soft nub is good. What I'm planning on doing is putting some nerf dart foam on the arm as a nub. The process you stated above is basically it, though I would suggest a TDC mod because you can fine tune it much easier. Just make sure the hop window has flat walls. My edgi barrel had rounded walls that I needed to file down.