Read "HTHWay" the other day, again. Reading the part on broad heads. Howard explains the BH should be a MAXIMUM of 150g.
Now, as he aged and settled into 75# bows think about it for a minute. 75-80# cedar and a 150g head. Makes a 600g arrow. That would be a reliable middle of the road weight for that spine class weight. 8-gpp
If one shot, say, 45-50# with a 150g head they would be lobbing 525g shafts. 11-gpp rainbow brights
The shafts are a bit lighter in this spine range so to keep arrow balance in line with this weight class say we drop down to 100-125g heads for approx. 450g arrows, lighter spine, point, still tail tapered, etc etc..
Now I know 100g equals 1/4oz, an absolutely humungous load, I still would not let anyone shoot it at me!
Well I did it, custom Dremel tool 100g heads. Much, Much better brush arrow. Nice and flat, plenty of smack. :cool: