Is the Buffalo bow cut to center or past center? 2016s spine about 60#. I'm assuming you're shooting a fast flite type string. That, and the relatively heavy head, which softens the spine and 1 1/2 inches of arrow length that you don't need, which also softens the dynamic spine means you might just need a little more arrow spine, particularly if your bow is cut past center.
Start by dropping to a 125 grain point. Or cut off an inch of arrow length. Each will have about the same effect. Both will double the increase in dynamic stiffness. In short, a 2016 should work with your set up if you can find the right point weight and/or arrow length. Good luck.
P.S. It also could be that your form is inconsistent, of course.