I have a 6.5/284 being built right now on a M721 action(no sleeve). I had hoped to use NightForce tapered bases and NightForce rings but I remember seeing somewhere that the earlier M700s had a different rear reciever bridge height than the current production models, which my bases are designed for. This causes binding of the scope tube. Will this be something I have to worry about with the M721? I think the difference was about .017" --too much to lap out. I plan to lap the rings, just wondering if I'll need to make a shim, too?