Have a tech question!
#1
![Default](https://www.huntingnet.com/forum/images/icons/icon1.gif)
I shot the 115 gr. Muzzy 4 bladed broadheads for some time now and shot very good with them. This year I thought of switching to the Muzzy Phantoms. Well I shot the 125 gr Phantoms at 20 yards and they were all over the place. Put my 115 gr back on and cut fletchings. So my question is why are they flying all over the place and would going down to 100 gr help? I am shooting @ 70 lbs & 29" beman carbon hunter (400)arrows w/ 4"vanes. It's not like they are hitting in a different spot, which I would expect, they are all over. I shoot the 115 gr and field points @ 1" at 20yds. I will probably just end up sticking with the 115 gr 4 blades, but really thought it would be nice to shoot the phantoms. And yes my bow is tuned, I get it checked every year!
#2
Giant Nontypical
Join Date: Feb 2003
Posts: 9,175
![Default](https://www.huntingnet.com/forum/images/icons/icon1.gif)
I hate to burst your bubble, but your bow isn't tuned, at least not tunedto arrows with 125 gn Phantoms. When you change anything about your setup, especially something as critical as broadhead weight,it always requires the bow to be retuned.
That's one of the very best reasons to learn to tune your bow yourself. It gives you a lot more freedom to play around and experiment with different arrow/broadhead combinations without having to be constantlyrunning back and forth to a shop.
Another thing is that it couldbe that you are right on the raw edge of arrow spine for those 400's with 115 gn heads. Underspined arrows won't hardly ever shoot to the same place twice in a row.It's very possible that you need to change to a stiffer arrow for 125 gn heads. If you did your own tuning, you could back off the bow's draw weight by 5 pounds and test whether arrow spine is the issue.
That's one of the very best reasons to learn to tune your bow yourself. It gives you a lot more freedom to play around and experiment with different arrow/broadhead combinations without having to be constantlyrunning back and forth to a shop.
Another thing is that it couldbe that you are right on the raw edge of arrow spine for those 400's with 115 gn heads. Underspined arrows won't hardly ever shoot to the same place twice in a row.It's very possible that you need to change to a stiffer arrow for 125 gn heads. If you did your own tuning, you could back off the bow's draw weight by 5 pounds and test whether arrow spine is the issue.
#3
![Default](https://www.huntingnet.com/forum/images/icons/icon1.gif)
Take the cutter blade out and see how they fly after that. I have the 100gr phantom with the cutter blade that can be removed but I dont need to. Mine are shooting fine but will only use them if Im in a pinch.
#4
![Default](https://www.huntingnet.com/forum/images/icons/icon1.gif)
I agree with Arthur in that your arrows are way underspined for the weight and length, with a 125 gr broadhead. Probablt with 115's, too, but apparently you're getting away with them.
Can't say why people don't think about it, but with an underspine issue the cheapest and easiest way to get them to fly is just drop some draw weight off the bow. Alas, most people are averse to this as they think they need tons of KE to get the job done. Seems that one of the best tuning gadgets put on a bow are the last to be considered to get good arrow flight. They are called limb bolts. Bows are adjustable for a reason.
Can't say why people don't think about it, but with an underspine issue the cheapest and easiest way to get them to fly is just drop some draw weight off the bow. Alas, most people are averse to this as they think they need tons of KE to get the job done. Seems that one of the best tuning gadgets put on a bow are the last to be considered to get good arrow flight. They are called limb bolts. Bows are adjustable for a reason.
#5
![Default](https://www.huntingnet.com/forum/images/icons/icon1.gif)
Thanks Arthur. Yes I am capable of tuning my own bow. I have done some further info hunting with the arrows and I am underspined with the 125's. I am going to go ahead and get the 340's which will work fine w/ the 115's if I go back to them. The 115's are borderline 400-340. Thanks!