Lost 2 arrows at 40 yads, WTF?

[erik1972]

So I finally got around to shooting outside at longer ranges with my new Mathews Z7 this weekend. I got field tips all dialed in out to 50 yards no problem. I screwed on some broadheads just to see what they would do. 20 and 30 yds perfect, 40 yards 3 inches low. Then the bad stuff started. At 50 yards 2 broadheads dropped 2 feet in front of the target, WTF!!

I went back to the field tips and did some walk back tuning and everything is fine. I do/did have one arrow that wobbled a little. But what the heck would cause a 15" drop between 40 and 50 yards?

I am shooting a new 28" Z7, 65lbs, Goldtip 5575 XT Hunters at 27" with a 100gr tip. The one arrow I lost had a Slick trick on it.

Where should I start looking as far as tuning goes? IS it my bow, the broadhead, to stiff or weak arrows?

Any help would be great!
Thanks Erik

 

[bayside]

I've never shot those broadheads. My grim reapers fly EXACTLY like my field tips. My guess is it's the broadheads.

 

[Boskee]

LAST EDITED ON Mar-22-10 AT 10:07AM (MST)[p]I would look at your rest if it's a drop away. It would appear that it's not coming up to the same level with each shot. While you may get some eratic flight with broadheads if they're screwed on straight weigh the same, unless they're hitting your sight or something there shouldn't be that much variation. A crooked broadhead will give you fits on some bows. Slick trick are low profile heads and normally fly pretty well.

 

[BigPig]

Its not the broadhead. Was it the same two arrows diving down and the others were OK? You might just have a bad couple of arrows/inserts. Sounds like contact or uneven up or down nock travel to me. Rule out contact with lipstick or foot powder first. Then try paper tuning at multiple distances. Your set up sounds fine. My guess is an arrow construction issue, contact, and or tuning.

 

[erik1972]

LAST EDITED ON Mar-22-10 AT 01:17PM (MST)[p]LAST EDITED ON Mar-22-10 AT 01:16?PM (MST)

I just got off the phone with the bow shop and told him what was going on. He said this be the second Z7 in a week this has happened to. He said he is confident that after 300-400 shots my string has probably stretched some and my knocking point has moved some. He wants me to check that my arrow is parallel to the shelf. He said if your knocking point moves it amplifies with a broadhead and out to longer distances. What doesn't make sense is the huge drop between 40 and 50 yards. This arrow dove straight down after 40 yards and didn't even hit the target.

Unfortunetly I lost the arrow so I will never know if the tip was not screwed on right or anything. I will check on some things tonight.

Erik

 

[BigPig]

that actually makes perfect sense as it would cause unlevel nock travel. Strings do stretch a bit inititally, even good ones. mathews strings tend to stretch a lot, and keep stretching. Why that bow company can't come up with a decent string is beyond me.

 

[EROCK1313]

Another thing to maybe consider based off how you mentioned you started at 20 yards and moved back to to 40 with broadheads is; how close were your groups and how many shots at each of those ranges before the failure? If your groups were fairly tight, any one of those numerous shots from your broad heads could have sliced the fletchings upon arrival to the target on those two arrows. Close shots didn't show much variation, but longer shots and the more the arrow spins and has arrow resistence, could have been at play.

I did this same thing a couple of times, but after I figured it out, I decided to experiment and I sliced the remaing fletching at about halfaway in height from front to back and the other arrow's fletch at about 3/4ths height. I then shot my good arrows and then the two bad ones.

Reasoning: I wanted to get an idea at different ranges, how much a torn Fletch would affect my arrow flight and learn a little just in case I was in a survival situation and part of my fletching was damaged and I had no replacements.

Result: With my QS XT Hunters, one of my arrows hit about 8" inches high and the other about 4-6" low, but both still maintained their center (or at least fairly close).

The nocking point would have been my other suggestion. Let us know what ends up being the culprit!


?-ERock-> ?

 

[Boskee]

+1 big pig I didn't think about the nock thing but it can have the same correlation to the rest not coming to the same position with each shot. string stretch can effect the rest too.

 

[erik1972]

I will check my knocking point tonight when I get home. Its just tough to understand how an arrow going 290fps can take a nose dive between 40-50 yards. I wouldn't be so concerned if it was super low at 40 yards but 2-3" could of been me as well.

We'll see tonight. He also mentioned something about adding a broadhead seems to make some arrows act weaker spined.

Erik

 

[erik1972]

So I followed what the archery shop told me to do last night and found a few things out. I don't have archers level/square so what I did was knock an arrow raise the rest as if I was at full draw. I then layed another arrow on the shelf of the bow just underneath the knock arrow. At the rest there was probably 1" in between both arrows. At the other end there was maybe 1/2" between the arrows, so the knock arrow is definetly pointing down or knocking point is high.

I heard some people talk about knocking point should be 1/8" above level and stuff like that. So I am not sure what to think right now.

Thanks, Erik

 

[blazingsaddle]

One more thing to look at- make sure your BHs spin true. I don't know if they had been shot before or they were brand new, but a bent ferrel will cause very bad flight.
I shoot Slicks and all of them have spun VERY well straight out of the box.
But it sounds like you need to let your string settle then move things around. Or if it were me, replace the sting, if what bigpig said is true about mathews strings.(which I'm sure it is)

 

[cantclosethedeal]

One of the reasons I like fixed blade broadheads is that they MAGNIFY tuning problems. If I were to switch to an expandable, I would still tune with fixed broadheads first.
One item that has not been discussed is the possibility that his broadheads are opening during flight. This will surely cause the rare but erratic flight he is describing.

Good Luck

 

[erik1972]

These are fixed broadheads not mechanical. But you are right, I am sure if I screwed my Rages in they would fly perfect as well.

Erik

 

[BOHNTR]

If you can't achieve consistent arrow flight with a Slick Trick then there are other issues as mentioned above. They are one of the better flying short design heads out there.

BOHNTR )))---------->

 

[springbear]

I have always had better luck shooting broadheads with feathers and a pretty stiff helical on them... this will help out if you have a little bit of tuning isues as well.

you did not mention how your arrows are flethced. I have seen what you described happen, but only with vanes on. even the short stiff ones, though not as much.

I am not suggesting, it is a "cure", but it can help.