Broadhead Tuning Issue

[rjlefty3]

I've been working on broadhead tuning my bow for a bit now and can't seem to get my broadheads to hit with my field points.

My broadheads (Muzzy 100's) are consistently 3-4" left (I'm a lefty) of my field points at 40-50 yards. The difference is only 1-2" at 20-25 yards. I moved my rest right, only to have both tips move the same amount towards the right and still be 3-4" apart.

I don't feel it's my shooting - I'm shooting consistent groups out to 50 yards with both tips. I also don't think I'm torquing my bow, although I don't really have a good way to know for sure. My shots feel good and I have a sight level that I've really been focusing on. Is a sight level enough to know if you're torquing a bow?

I'm thinking it's because my arrows are underspined. My bow is at 68#, 28.5" and I'm shooting gold tip velocity 340s. At the time I bought them GoldTip's chart said borderline 340 but really close to the 300s. They've since updated their chart which now says I should go with the 300s.

Just curious if this could be due to the underspined arrows? From what I've read about, it seems like it would be. I'd just like a couple of opinions before I go ahead and buy a dozen 300 shafts. Thanks for any help!

 

[JohnCushman]

I had the same issue with Muzzy MX4's. Properly tuned bow, paper tuned and walk back tuned and properly spined arrows for my bow set up. The broadheads hit 3 inches low and left consistently from my field points.I put on a buddy's Slick Trick 100 grain mags for the heck of it and they hit within an inch at 40 yards. I tried Shuttle T's on the advice of my bow shop and they hit within a half inch at 40 yards and with a little adjustment were dead on all the way out to 60. So, I have stuck with them and they have been brutal on everything I have shot with them. I have heard of a lot of tuning issues with Muzzys...but I know a lot of guys that they shoot well for...so, this is just my story for the sake of conversation and not to start an argument.

 

[Deleted member 20812]

The first thing you should check for is string/cable contact. Put lipstick on your vanes and shoot, you'll see right away if you have contact.

My honest opinion is that it's torque. You don't say what kind of bow, but I don't think you are underspined. I shoot 67#, 28.5 arrows with 125 grain tips out of my Bowtech Experience and have excellent broadhead flight.

The consistency of your groups is irrelevant. You can have bow torque and still shoot very accurately.

Have someone watch you shoot from behind. My guess is that when you come to full draw, they will see that your bow string does not come off of your cams in a perfectly straight line.

Your grip hand should be at about a 45 degree angle. The grip should NOT cross the line that runs from the center of your palm towards your pointer finger. Your thumb and fingers should be relaxed and just lay along the grip of the bow. Experiment a bit with the position of your wrist. A high wrist, that is pretty straight is more likely to induce bow torque. You may have to drop to more of a low wrist position.

 

[Bulldog0156]

If your inserts aren't in straight that could easily be the problem. I had that issue last year for a few days before I figured out the problem. I also knew it wasn't a spine issue though because I've been shooting the same setup for a few years.

 

[rjlefty3]

Cush - I've read about similar stories. I'm hoping I don't fall in that category! Worth a shot to at least mess around with that possibility though.

JLS - I don't think I have contact, but I'm going to try that trick and make sure there isn't any.

I'm also shooting an experience, basically the same set-up as yours with the exception of my 100 grain head, but I also added a 50 grain screw in weight to get my weight up.

I'll try messing with my grip a bit. My grip is fairly high, so I'll try dropping it like you said and see what that does.

Like I said, I have no idea how to tell if I am or aren't torquing it so you're probably right. I added the grouping part since it was my 'quality control' measure, haha! I assumed that torquing a bow would affect groups the same, but it seems like broadheads would be more sensitive to the issue?

Thanks for the tips and help guys, I appreciate the help!

 

[Deleted member 20812]

I've found that I shoot best with pretty low wrist with this bow.

I had a Mathews Q2 before this. I changed to a Torqueless grip one year, and when I went to tune broadheads I was absolutely pulling my hair out with exactly what you described. My BH would hit right of my FP every time, but yet my groups were excellent. I tried different heads, different weights, different fletchings, different arrow shafts.

Finally, a guy on Bowsite asked me about my grip. I started playing with it, as I could look up at full draw and see a slight cant where my string came off of the idler wheel. After altering my grip I found my problem and was able to tune my BH to my FP no problemo.

Pull the 50 grain inserts and see if the problem still exists. That will rule out or identify spine pretty quickly.

 

[rjlefty3]

If your inserts aren't in straight that could easily be the problem. I had that issue last year for a few days before I figured out the problem. I also knew it wasn't a spine issue though because I've been shooting the same setup for a few years.

That would be the last thing I would look at! Pretty sure I'd buy new arrows and say those worked instead without even knowing.

 

[rjlefty3]

I've found that I shoot best with pretty low wrist with this bow.

I had a Mathews Q2 before this. I changed to a Torqueless grip one year, and when I went to tune broadheads I was absolutely pulling my hair out with exactly what you described. My BH would hit right of my FP every time, but yet my groups were excellent. I tried different heads, different weights, different fletchings, different arrow shafts.

Finally, a guy on Bowsite asked me about my grip. I started playing with it, as I could look up at full draw and see a slight cant where my string came off of the idler wheel. After altering my grip I found my problem and was able to tune my BH to my FP no problemo.

Pull the 50 grain inserts and see if the problem still exists. That will rule out or identify spine pretty quickly.

Is there a good way/trick to see if knowif you're torquing the bow?

 

[Deleted member 20812]

Is there a good way/trick to see if knowif you're torquing the bow?

Come to full draw and look at the angle of the string relative to the cams. It should come off of them perfectly straight. If there is any angle at all, you are torquing the bow. Sometimes this is easier to do with another person.

Also, make sure you aren't torquing your release arm either. A slight "@#)(#" in your wrist or pressure with your release hand can create problems also. Should be able to relax your hand and wrist, and your release arm is a straight line from your arrow tip to your elbow.

 

[JohnCushman]

*in my best Beavis and Butthead impression* heh heh heh he said @#)(#

Damn it's great to be 43 and so juvenile

 

[JohnCushman]

RJ...come to full draw and have someone take a pic and post it on here

 

[rjlefty3]

Come to full draw and look at the angle of the string relative to the cams. It should come off of them perfectly straight. If there is any angle at all, you are torquing the bow. Sometimes this is easier to do with another person.

Also, make sure you aren't torquing your release arm either. A slight "@#)(#" in your wrist or pressure with your release hand can create problems also. Should be able to relax your hand and wrist, and your release arm is a straight line from your arrow tip to your elbow.

I guess you mentioned that above. Didn't realize it was for torque, sorry! Looks like my wife gets to help me out again. She'll be thrilled, I'm sure!

 

[rjlefty3]

RJ...come to full draw and have someone take a pic and post it on here

Not a bad idea. I'll shoot a bit with the grip changes and see what happens. If nothing changes I'll post one up. Hopefully it's just a torque issue and nothing else .

 

[JohnCushman]

Shoulda bought a Mathews

 

[rjlefty3]

Shoulda bought a Mathews

Took you until post #14? You slacking or just being nice?

 

[JohnCushman]

Trying this kinder gentler Cush thing

 

[TimeOnTarget]

I know you said your bow was tuned properly, but have you checked cam lean and cam timing?

Have you done walk back tuning with just field points?


Torque could also be the cause.

I dont know which sight you are using but have you set your 2nd and 3rd axis?

It's very possible that there is more than one issue in play here.

 

[Dan O]

The arrow charts are only a guide line. If you take into account the speed of your arrow can vary significantly depending on your bow. Using the draw weight is only a starting point. The important thing IMO is the arrow speed. I have been using goldtip pro 300's for a number of my bows and they have tuned well. It has worked with all my 70# Bowtech's, 82nd, Admiral, Insanity and Experience. I have used 125 gr Magnus Stingers and 100 gr Slick Tricks. You need to spin test each arrow with the broadhead on it. Which 340 are you using? Pro is .001, XT .003 Usually the XT's will spin about 50% of the time perfectly.
I agree that the torque issue is probably the cause of problem. If you have a video camera set it up and record a dozen shots and each time you shoot a arrow describe where it hit in relation to your field point vs broad head group. Caution shoot the broad heads first at difference spots before the field points. No damaged arrows that way Then study the recording and see what your bow is doing before and after the shot.
Remember the faster the bow the more critical your form becomes. If this doesn't work go to your local Pro shop and see if they can help you out before you get frustrated and lose your confidence in your equipment.
Good Luck,
Dan

 

[shoots-straight]

I would go to the 300's shaft. I shoot close to what you do, and thats where I'm at. Spine IMO is the biggest issue.

 

[rjlefty3]

Thanks for the help guys!

I haven't addressed cam lean/timing. I don't really have any shops (at least good ones) nearby so I'm trying to figure this out on my own. Even the closest shop ships your bow out to be tuned, so you don't even get to shoot it/tune it yourself. I was putting this issue at the back to make sure there wasn't anything simpler first.

I'm shooting the step below the XT, the .006 one. I figured that's too small of a difference from the pros/XTs for an amateur like me to even notice.

I'll try the grip change first and see what happens. I'm hoping that's the issue!