Well, I got my problem fixed. My current setup is a R/D Hybrid (I know it's actually D/R) at 41# shooting a 29" Carbon Express Heritage 150 with 5" feathers and 100 gr. field points. I was getting a lot of erratic arrow flight, and very inconsistant groups. I used the Dynamic Spine Calculator to determine that I need 250 to 255 grain point on my arrows to get the spine right. While at the local archery shop shooting, I had a conversation with one of the guys behind the counter about adding weight. He said that we could try the new Gold Tip end-load weights. So, we removed the nocks, and using the tool Gold Tip supplied to them, we added 120 gr. of weight to the inside of the arrow at the insert, and put 125 gr. field points on them. All I can say is WOW! It was like I was shooting a completely different bow. My groups were tight, and consistant and the bow was much, much, much quieter with virtually no hand shock. I could not believe the difference it made. I shot for over 2 1/2 hours. Oh, I still shanked a few shots, but the arrows flew like lasers to the target. So, if you're shooting carbons and want to add weight, check on getting you some Gold Tip end weights.
D.A.