So I have always shot Ironwill Broadheads and they always fly like darts. I bought a new bow this year and I can't figure out why my broadheads are flying so poorly. First my set up is as follows: A Mathews V3 31 with a 28.5" draw at 70 lbs. Shooting Easton 5mm FMJ's 340 spine that are 27" and 3 fletched with blazer vanes and a wrap underneath. I have a Ironwill 100S up front. Total arrow weight is about 462gr. My field tips and my mechanical broadheads fly perfectly all the way out to 80 yards and hit the target right where I am aiming. When I shot my ironwill's today the first shot was at 20 yards....I missed about 18 inches right and into my fence. The second shot was at 8 yards and I hit about 4 inches left of the center. The third and final shot was at 20 yards and now missed 12 inches left into my fence. When shooting at 20yards I could almost see my arrow dancing or knuckling in the air. I basically watched it take a hard right or left off target. I switched back to field tips and NAP mechanicals and they flew perfectly at 20 yards and 40 yards. My guess is that I am underspined at 340? I ordered some 300 spine arrows that I am going to 4 fletch rather than 3 fletch hoping that solves the problem? Any other suggestions? Thanks guys!
I’m not the smartest at it but based off the FMJ spine chart, 28” draw at 70 pounds is barely inside 340 and you add a half inch. Probably underspined. With the extra ten pounds it probably just flexes that arrow that much more and is hard to zero broad heads but I’m sure smarter dudes will chime in soon Sent from my iPhone using Tapatalk
Underspined but not by a lot. And FMJs are pretty stout. But then again Iron Wills are basically big wind planes so maybe...but to be that off at 8 yards seems to me would not have time to shear that bad.
I shoot almost the same setup but I'm 29" and shooting 75 grain brass up front, and I have no issues with being underspined with Axis 340's. It sounds more like a tuning issue to me than anything. The massive inconsistencies with hitting left/right are a bit troubling, though. You could have some sort of rest contact issue as well. What steps have you gone through to make sure the bow is properly tuned? An have you spun your arrows with the broadheads on them to make sure they're not wobbling?
Double check the weight of the broad heads. And this ^^^ are the arrows spinning really tight on a spinner with those broadheads attached? And if at all possible, try and capture a high speed video (assuming you have phone for it) to watch arrow reaction when it leaves the bow...similar to this: (used a samsung galaxy 9 or 10 for this)
Probably going to catch some flack for this, but it has always been a really good starting point and a sort of control test when I tune. What does a bare shaft look like through paper? Where is a bare shaft with field point hitting compared to fletched arrows?
I agree with Justin, this doesn't sound like it could be an underspined issue. It's too drastic, plus the weight of the heads is the same. If the IronWill's were drastically heavier then perhaps. It's very odd to have left and right issues with the IronWill's but then a different head of the same weight flies fine on the exact same arrow. This means it shouldn't be a fletching contact issue. I'd assume the Blazers are capable of steering your IronWill's since you've ran that setup before with no issues. I'd think you'd have noticed if the blades were making contact with your riser. A 27" arrow with a 28.5" DL means the head is sitting over the shelf I'd bet, but would think you'd notice if a blade was making contact with the shelf at full draw. Still, make sure you don't have a blade barely touching or sitting really close to the shelf at full draw. So, just changing to a fixed head creates drastic problems. Has to be either the centershot/tune on your bow is way out of whack or the IronWill's aren't screwing into your inserts nice and straight. Spinning them with the IronWill's installed will answer if they are mounted to the arrow nice and straight. Fixed heads are much harder for fletching to steer, so it is possible that a poor centershot is being overcome by the fletchings with field points but then once those wind planing fixed blades are added the fletching simply can't correct it. Shooting through paper at 6' with a fletched field point, or shooting a bare shaft (field point) into a compressed layered foam target at about 5 yards along with a fletched arrow will show how good the centershot is. The bareshaft should go to the same POI and be in the target at the same angle as the fletched. Make sure the target doesn't pivot between the two shots so you see a different angle because of that. 1. Make sure it looks like there's no contact anywhere while at full draw with the IronWill's. 2. Spin the arrows with the IronWill's to make sure they are true. 3. Check tune of the bow, paper tune or bare shaft tune.
You almost definitely have a contact issue, it’s probably slight because it’s only showing up wit broadheads. You either have slight fleeting contact with your rest or it’s slow to drop
What fletching is on the the arrows? If it is blazers, I am guessing you have a fletching contact issue. I had that problem a couple of years ago. I switched from Blazers to a Bohning Heat vane, slightly longer but with a lower profile. It resulted in an immediate correction of the problem.
UPDATE: So I switched from my Bohning Blazer 3 fletch to an AAE Max Stealth 3 fletch and it corrected the crazy flight. It appears my Blazer vanes were hitting the roller guard when executing the shot. The only problem now is that my broadheads are grouping about 8 inches low at 20 yards compared to my field points. Still working on figuring out how to correct this without completely changing my sight. I am fletching up an AAE Max Stealth 4 fletch right now to see if that maybe adds some more stability.
Good deal, glad you figured out what was causing the erratic broad head flight. To correct the BH's hitting lower than your field points you need to raise your rest a bit. 8" low at 20 I would move the rest up about an 1/16" to start. After that make small 1/32" adjustments until you are getting same POI. Then you'll need to adjust your sight frame accordingly, most likely it'll need to be moved up a bit.
I really didn't think it would be since he said fletched were flying great to 80 yards. Ironic, I was shooting my new bow this weekend and found that I was getting some fletching contact. I put a limb driven Hamskea Trinity on it and the little rubber arrow guide you put on the end of the shelf was making slight contact with my lower left vane. Not enough for really erratic flight with fletched field points, but enough that my groups were worse than what I can normally expect. I'd imagine a BH would've shown it much worse.
Had this with my Day Six EvoX last year. I complained they didn't work to the guy and felt bad after I finally figured it out. 1. I tuned the arrows through paper (Mistake I made was shooting fletching's) 2. After getting pissed because my bow was "tuned" I didn't know what to do after watching arrows fly sideways at 40 yards... 3. I took my bow back to the shop and we "micro tuned" it. Stripped the arrow, bare shaft and a twist here and there, made sure the drop away was timed with the speed of the bow, and sure shoot it was pounding dimes with broadheads after it... I also shoot vap TKO's which are spine aligned, this means you should always have the arrow drawn on your arrow (Markings put on by Victory archery that say "Spine Aligned") on top.
