120 gr addition of weight means a slight loss of KE? I'd like to chrono my bow and see that. If I'm wrong I have no issues admitting that, either. Promise.

If I switch to a COC fixed head for a while......I won't worry too much about the KE. People shoot WAY less pounds and speeds than I shoot with those heads. THE reason I strive for more KE is the fact I shoot the mechanicals.

What's the heaviest arrow I can shoot that's properly spined (if I shoot a 100gr. head)? Also....what's the effect on spine? FOC?