Issues tuning my bow for fixed blade broadheads

[Rolfes10]

Here's my setup: I shoot a Mathews Z7, 28 inch draw, 70lbs, Easton FMJ's 340 cut at 29 inches with a 50 grain insert which brings me up to 515 total arrow grains, Slick Trick 100 grain standard.

Here's my issue: The slick tricks shoot very similar to my field points out to 40 yds. As soon as I hit 50 yds, they start fading 3 inches to the right. When I move back to 60, they increase to 6 inches right. Ideally, I want (and expect) these Slick Tricks to shoot identical to my field points out to 100 yds.

My bow is tuned as best I know how but I could be missing something. Paper tuned and shooting bullet holes at 4-6 ft. Bottom cam is in tune and wheel is in alignment. Am I missing something??

I'm still trying to trouble shoot but need some tips. Any info would be greatly appreciated!

 

[ando_31]

What is the length of fletching?

 

[Cobbhunts]

Based in what you have stated, its most likely in your rest. Google walk back tuning and use that method. I also like to paper tune with a bare shaft. It will really show any imperfections in your set up. But a word of caution....if you bare shaft tune, your form and grip have to be perfect. Which is something else that could be causing your impact issues at longer ranges with fixed blade heads. Good luck!!

 

[Cobbhunts]

Also....the 50 grain insert will weaken your spine, but shooting the FMJ 340 with the Z7 @ 70lbs you should still be within tolerance.

 

[Rolfes10]

My arrows have 2'' blazer veins on them now but have thought about trying 4'' veins or a more aggressive helical with the blazers to help stabilize the arrow. But I'm not sure this is the issue.
I have walk back tuned in the past but not recently. I will do it again to make sure but when I shoot my field points, they all fly perfectly in line from 20-100yds and don't experience any fading left or right.

 

[mnhunter]

broad heads will expose small imperfections in your tuning. If I were you I would try bumping my rest over just a hair and see if this brings them in.

 

[tdcour]

Rolfes! Nice of you to finally join! My offer still stands about the new fletchings on that 14 hr drive... Oh, don't forget to introduce yourself in the new members section so we can get your honey holes

 

[MRC]

The 50 grain insert wont decrease arrow spine but it will in fact change the FOC. Like the other members were saying you should start with paper tuning and if your golden there should be no reason to move your rest left or right for adjustments. When FOC is out of spec your arrow will "lean" forward and use the broadhead to steer it rather than the vanes. My suggestion would be to double check your FOC with the calculator, if your in spec then double check tear on paper, then after that try shooting the same arrow with the same broadhead and see what happens. One by one you will be able to eliminate sources of problems. Good luck!

 

[Hilltop]

This is reason #1 that I have switched over to all expandable broadheads... The kinetic energy with your setup is high enough that penetration, IMO, shouldn't be a concern. Send me a PM if your interested in more of my biased opinion

 

[25contender]

I shoot almost the exact setup on my Z7. I would go with the standard insert. I am shooting 29" ACC prohunters, 2" Blazer vanes, Slicktrick Magnum 125s. @ 70lbs. Drop away QAD. They shoot perfectly all the way back. Might want also check to make sure all your pins are parallel to your string. It doesn't take much for your arrow to fade one way or another if your sight is not square to the string.

 

[Cobbhunts]

The 50 grain insert wont decrease arrow spine but it will in fact change the FOC. Like the other members were saying you should start with paper tuning and if your golden there should be no reason to move your rest left or right for adjustments. When FOC is out of spec your arrow will "lean" forward and use the broadhead to steer it rather than the vanes. My suggestion would be to double check your FOC with the calculator, if your in spec then double check tear on paper, then after that try shooting the same arrow with the same broadhead and see what happens. One by one you will be able to eliminate sources of problems. Good luck!

I hate to disagree, but added weight up front WILL weaken your spine. Weight added to the nock side will stiffen the spine.

And you are correct, the weight in front will increase his FOC, but I'm shooting a near 15% FOC currently and couldn't be happier. 502 grain complete arrow. I doubt his 50 grain insert is causing his BHs to steer the arrow over the blazers. It should however make them fly like darts, which is what mine do with a higher FOC.

I still bet its in your rest. And I'd try to do some walk back tuning along with bare shaft paper tuning if possible. Good luck!!

 

[Cobbhunts]

Download a free trial of OT2 software if they still do the free trials. Learn to use it well and it takes the guess work out of proper spine selection and calculates your FOC. Its a good program and worth the money to purchase it. The software requires very detailed input however, so garbage in garbage out. Make sure the data you input is accurate, and that's what you get back in return.

 

[Rolfes10]

I made adjustments last night and have my bow paper tuned with a bare shaft and refletched my arrows with a more aggressive helical. If this doesn't work I guess I'm switching to mechanicals. I'll let you know how it goes though!

Has anyone had experience with broadhead venting and how it can effect arrow flight especially at further distances?! Would a solid blade fly better than a vented one?

 

[BruinPoint]

There are at least 2 big things to consider that don't require Allen wrenches or money that can result in broadheads drifting to one side at 50+. First is whether you're holding your bow level. Even using a bubble level on your sight it could be off - get it in a bow vise and double check. Second is form, including hand torque and follow through. The helical vanes won't hurt anything but your setup should be shooting laser beams either way if your tune is on.

 

[OregonJim]

There are at least 2 big things to consider that don't require Allen wrenches or money that can result in broadheads drifting to one side at 50+. First is whether you're holding your bow level. Even using a bubble level on your sight it could be off - get it in a bow vise and double check. Second is form, including hand torque and follow through. The helical vanes won't hurt anything but your setup should be shooting laser beams either way if your tune is on.

I was just about to chime in with similar comments .
I am shooting left handed. I'm actually right handed but left eye dominant (thats another long story).
Both my bows (A DXT and a Bowtech Admiral) are set up correctly although lighter poundage with appropriate shafts.
I have the similar problem in reverse. It is darn near the same problem with both bows and only shows on broad heads.


I had some folks watch and critique me on form. Sure enough my problems are self inflicted (grip, not getting the bubble in the middle).
Mechanicals are not legal in Oregon anyways but I could go to them for out of state hunts.
I used them for years on deer but I am just not comfortable with mechanicals on elk from a 60lb draw.

I know it may sound strange but my 6 inch drift left at 50 is so predictable with 100 grain thunderheads that i have become comfortable with it. It has become almost like holding high at a longer range. I have shot my last two elk at 50 and 50+ holding 5" and 7" right.

Oh, and both were heart shots!

 

[Work2hunt]

I'm no expert, but I've tried both of these to help me.

http://www.eastonarchery.com/downloads/tuning-guide

The very bottom of post #1 will lead you to a pdf. It is pretty long but comprehensive.

http://www.archerytalk.com/vb/showthread.php?t=1399457

 

[RockChucker30]

I shoot a 28.5" FMJ with 100 gr slick tricks from a 70 lb carbon overdrive.

Check out the broadhead tuning sticky on archerytalk. It'll get you dialed, but be aware that past 50ish the increased drag of the BH can cause you to hit a little lower.


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