broadhead flight with over spined arrows

[yakimarcher]

I have a dilemma with my bow! I shoot a year 2000 martin scepter set at 65lbs, 29” draw, new string in the spring of 2015, release shooter, 30” Easton aftermath 340’s with 4” right helical fletching and magnus stinger 125 broadheads. Last year my broadheads grouped with my field points and all was well with the universe!

This spring and last winter I didn’t shoot my bow at all, and I got it out in late June. I had previously been using a tubeless peep sight and that didn’t work out so well, it would never align just right and I would always have to be turning it with an arrow nocked so the nock would hold it’s position. I switched it out for a tube peep and got back to shooting. Immediaetly my bow was shooting 6” low at 20 yards, I adjusted the sight and shot a lot (with field points), getting good groups out to 50 yds. And all was well until…

I started shooting with broadheads a couple weeks ago and they didn’t group with my field points! (they had before) I adjusted for nock point height until they were on the same horizontal plane, but the broadheads still hit to the left indicating that the arrows are overspined, I adjusted my arrow rest to the right and it closed the gap slightly but if I move the rest too much more to the right I will likely get some fletch contact with my riser. The sight is now adjusted to the broadheads, which is likely how it’s going to stay until the end of the Archery season. I’m definitely not satisfied, I’m seeing some fishtailing and obviously the bow is out of tune.

What would cause this change in my bows performance? Limb fatigue, out of timing, string stretch, The draw length does feel slightly longer. Any suggestions, I really don’t want to buy new arrows and the only archery shop in town is closed until hunting season is over so a new string is out of the question.

[DaveMonti]

My bow has a similar problem with the broadheads impacting to the left of my field points.  I made some adjustments on my rest, but finally decided to just practice with the broadheads and worry about it later.  I am consistent out to 60 and while I have a slight fishtail every now and then, I attribute that to grip inconsistency. 

To be honest, I don't recall if I've ever had broadheads and field points impacting the same.  Perhaps I just never put enough effort into tuning.  From the literature, I have the appropriate spine arrow and am shooting well with practice broadheads, so I'm good for this year.

[coachcw]

your bow is out of tune ! check cam timing first things first , your not over spined

[yakimarcher]

thanks guys! When I got the new string in the spring of 2015 Mike at Grizzly archery re-set the timing. I'm wondering if the string stretched and its out again. thanks for the input!

[Redbeard]

Did you get a quality string or a cheap string off some guys website? There is a difference. Also sounds like you might have some cam lean going on also. (Giving the shooting to the left. Take your bow to a quality shop ( Not Cabelas ) and get it re tuned.

[pope]

Broadheads are the same grain/weight as field points? If not, remember heavier points result in lower spine. A possible explanation for shooting left would be broadheads with weight lower than your field points, resulting in "stiff" arrows which will shoot left of your typical groups. Another possibility is that broadheads change your peripheral view and completely sabotage everything you've learned while shooting field points. I shoot traditional and this was definitely a problem until I reminded myself to think about form and only concentrate on the target.

[coachcw]

they both shot well last year . remember you have a year and a half on those strings , I'm sure they are settled a bunch . I change my strings on my hunting bow one a year and every other on my back ups . if your any where near Enumclaw run into rock creek and have Denton tune it up .

[demontang]

I'd say tune. I'm shooting 300spine arrows out of a 58lb set bow and have zero issues.

[Jellymon]

Are you shooting a drop away rest? 9 times out of ten with modern equipment when broadheads hit left of field points you move your rest LEFT. Broadheads right of field points you move the rest right. I know this seems backwards but it is the correct adjustment. That is if your yokes were set up correctly when the strings were changed.

[DaveMonti]

Are you shooting a drop away rest? 9 times out of ten with modern equipment when broadheads hit left of field points you move your rest LEFT. Broadheads right of field points you move the rest right. I know this seems backwards but it is the correct adjustment. That is if your yokes were set up correctly when the strings were changed.

I've wondered about this due to the design of drop away vs. contact type rests.  Is there any literature that supports this?   I've googled "drop away rest tuning"  and "Drop away rest adjustment" and I don't see anything about moving the rest opposite with a drop away vs. a contact type rest. 

It makes sense, but I can't find anything to support it.  The Easton Tuning guide does not mention anything about it either. 

Dave

[Jellymon]

Its not necessarily backwards, just correct the majority of the time. The easton tuning guide is out of date IMO and actually contradicts itself on this issue.

In the easton guide under paper tuning, a right tear (same as broadheads hitting left) it tells you to move the rest left. But under the broadhead tuning section it tells you to move the rest right. So which is it?

Not everything is set in stone with tuning, im just sharing my experience tuning many different bows. Vertical differences i move the broadhead toward the field point, and horizontal i move the field point toward the broadhead if my yoke tuning requires fine adjustment.

[yakimarcher]

Thanks guys, figured out it has a bad cam-lean issue. I'm just leaving it sighted in to broadheads and I'm buying a new bow after elk season is over.

[DaveMonti]

I did it all this past weekend.  Paper tuning, bare shaft tuning, broadhead tuning, walk back tuning, visual center shot alignment, and I just can't get the broadheads to impact the same as field points.  I changed to a heavier point (125 gr. from 100 gr.), tried 400 spine arrows (vs. 340s I've been shooting) and the cams are not out of alignment.  I give up!  I'll just go back to practicing with broadheads and chew up a few more targets. 
Frustrating. 

[yakimarcher]

Me too Dave! I shot 5 days a week for the last 3 weeks on my lunch break and a couple serious all afternoon tuning sessions, it's as good as it gets! I'm going to buy a new bow as soon as the 2016's go on sale, likely either a Hoyt Defiant 34 or a Bear BR33, heck i might even try out some mechanical BH's!

[JLS]

Davemonti,

Don't rule out hand torque