Where is the brass ejecting? Ideally,you want it to eject at the 3-4 o'clock position. If it is already ejecting at those positions, you are good, if not, go up until it gets that way. Each rifle is different, so you may have to experiment a little bit. It will also be different in the summer time. You might use a buffer that works perfect in the summer time and in the winter, it may short stroke and you have to lighten it up again. Noveske 6.8 rifles are generally a little overgassed because of all o the different ammo out there. For the 6.8, I'd stick with the 110-115 GR ammo.