Somebody give me a quick lesson.... What impact on arrow flight does the diff. weights have.... In selling my Rock, I kept all my broadheads and they are 100 gr. When I get my new bow, I will be shooting a different arrow....my Rock was shooting 6075 arrows....my Iceman will be shooting 250's. I'm curious how head weight impacts arrow flight. THanks SB
100 grain will fly faster and flatter. 125 grain slower, more drop, but will hit harder with more KE. There are also tuning impacts that others will be able to talk about in more detail.
Tip weight affects the dynamic spine. Increase the tip weight and the DS gets weaker, decrease and it gets stiffer. If you want to keep using a 100 gr tip then you just have to make sure you get the arrow length right, then small changes can be adjusted by changing DW or moving the rest. The bigger benefit of going from 100 to 125 would be a better FOC but a 25gr change is not going to be a real big benefit.
Some will say to pick the BH and weight you want to shoot and then tune for it. Others will say you should get your bow in perfect tune with field points and then your BH's will hit in the same spot (if you did it correctly.) I will say no more because I don't want to give a false impression that I know what I am talking about in regard to tuning.
I'll throw this out as food for thought... Many (if not most) people shoot 100-grain heads simply out of convenience and access; simply put, the selection of broadheads is FAR greater at 100 grains than it is at 125 -- though that has changed somewhat recently. Many people forget though that they can go with a heavier INSERT to up their FOC % and still have the wide array of 100-grain heads on the menu. That's the route I go; I use 50-grain Muzzy brass inserts in conjunction with a 100-grain head. Gets my FOC % up to where I like it and my arrows hit WAY harder. To Bruce's point, most people don't understand HOW much extra weight it really takes to affect FOC.
You brought up an excellent point about the inserts, Greg. I have that exact same setup, 50gr insert-100gr BH for exactly the reason you describe, BH selection. Definitely hits harder, busted the leg bone into pieces :D .
On a serious note. Since I currently have my bow shop cut, insert, and fletch my arrows I don't even know what grain insert I have. What is typical the insert weight? My FOC is just over 9% and I would like to get that up higher yet.
As long as I put em' where I'm looking they can fly any way they want! :D Pretty cool seeing my arrow drop right into the pocket!
If you make a significant change then you will have to make adjustments to your shaft or DW that will stiffen the spine. Lets say you add a 50gr insert. That is approx 35 gr increase of tip weight and you may just need to turn the DW down a pound or two. More tip weight would need bigger changes, maybe a combination of trimming shaft length and lowering DW. Edit: to add changing shafts is also an option, although more expensive.
Easy way to find out is just get yourself some heavy Field points and go from there! They make FP from 85 - 250 grains, hell there is a great selection of broad heads in the heavier range as well!
Keep in mind two things for my situation. 1. I have 350's right now so if anything - I am overspined and not underspined. 2. I am not in perfect tune right now (remember I am just now getting serious about tuning). My thought process is to get my rest changed (coming later this week), get my foc where I want it (appx. 12%). And then check/verify spine and then paper tune (checking DW, Length of arrow, adjust rest), then check with bh's. Sound reasonable?
If your going to change it like you said, why not beef it up even a bit more and get an even higher FOC? Put a 50gr insert and a heavier head, 125gr. You'll be surprised how harder your arrows hit and your bow will even be quieter! Just a thought!
Good thought however, I really want to stick with 100 grain (if possible) for availability. I really like the price ($32 per 6), sharpness and how these Wasp heads are flying for me. They currently make them in 125 grain but are pretty hard to find and rumor has it they are discontinuing the 125 grain model. BHC is out of stock right now for example and Cabala's is discontinuing them as we speak. For now my hope is to stick with 100 grain and look into seeing what a heavier insert will do.
There's a great article this month in Eastman's Bowhunting...regarding how much tip weight effects penetration. For this article - the author preached Momentum is more important than KE when it comes to penetration. For his test, shooting the same setup at 60, 70, and 80lbs...for each 50 grains added to tip of arrow, it was equivalent to adding 10lbs of draw weight in regards to penetration. Really opened my eyes...I'm going to do some testing with my set-up...I would really like to add a 100gr insert, if I can still tune and not shoot a total "rainbow" with my arrow.... ...good thread
