well it weakened it slighly but well withen the acceptable rangei went from 225 grain heads to 200 and they where stiff again so i went back to 225 and left it at that i expect if i fiddled with the fletching orientation it would work just fine, they are whisper quiet though
my arrows went from 520 grains to 660 i put 2 stick in each then took a tourch and hgeated up the entire shaft so they dont move around they havnt budged yet and they hit my target like a brick out of my 72# bowill let you know further updates when i get my 90# tuned