OK. At your 26-inch draw, you're drawing about 45#. I think the Apache is cut to about center and you're likely shooting a low stretch string. Though perhaps on the edge, because of the 250 grains up front, I really think those .500s should work for you. I shoot almost the same combination out of 45-50# bows with a 29-inch arrow and 28-inch draw. But some of my bows are cut proud of center, not to center.
Are you paper tuning or bare shaft planing? What distance from the target? Describe where the arrows are grouping or how the paper is torn. And whether you're right or left handed. Do you hear the arrow slapping off the riser. That would cause it to fish tail and could lead to a result that looks weak. So would a release that tends to pluck the string. On the other hand, if the bow is real efficient, cut past center and or you have a super low stretch string, they just might be weak. Can you take off 50 grains and 100 grains in point weight and see what happens.