Check on
www.bowjakson.com. I believe the shart you need to see is listed under the article about Kinetic Energy. What you are looking for is the AMO Minimum Arrow Weight Chart.
The 5gr/lb is accepterd by most but is not really an absolute. It can vary accroding to draw;ength, too, which most guys don't understand. It come down to how much stress is put on the system. Longer draws store the most energy and put more stress on the system. Short draw guys don't need to get all stressed out over it. You're close to 5gr/lb. Void your warranty?? Big question. Who's going to know unless you're dumb enough to tell someone.
That being said, if you are going to use this setup for hunting I would get some heavier arrows just for the sake of making the bow a bit more quiet. You'll lose some speed, but quiet is more important in the deer woods.
Of course there is another option that is a lot eaier and cheaper. Just turn the weight down a few pounds. There is no written rule that says you have to shoot 70# just because the bow is rated for it. There isn't a deer walking the planet that even knows whether an arrow is launched from a 70 pounder or a 50 pounder. When the arrow is in the ground after a passthrough the results are the same. The only thing that makes a difference is your testosterone level----and your shoulders about 20 years from now.
Different arrows
