I just ordered my 1st carbon arrows. Been shooting the 2315 I had, and been happy with them. You don't know untill you try. So I ordered Expedition Camo Hunters 7595. 27 inch @ about 425 gain. At first I was going to try to shoot the lightest I could get. After reading all the old arrow stuff, I thought 425 should be a good weight. I've still have the 2315 and 2317 to compare with.
BY my guess your going to be overspined, by alot. Anything 400+ is a great weight, unless your racewayking. Only people who hate walmart shoot under 400gr, haha
When I shot compounds I shot a 70 lb. 2004 Reflex Excursion (low price bow) and an arrow that probably had a total weight of 400 grains. Those 27.5 inch, 400 spine Beman's blew threw deer. I bet you will be just fine at 425.