Broadhead Flight

[CCooper]

I know broadhead flight has been discussed to nauseum prior, but I ran into an issue this week that I haven't previously seen.

I will preface by saying I generally do not perform any of my own bow work or tuning other than sight and small rest adjustments as I have one of the best shops in the country in my hometown.

I picked up a new RX8 this year and have been shooting 340 Axis with a 4-fletch Hybrid 26 vanes, IW collar, and 125 FP's for a TAW of 480 gr. Bow is currently set at 70LB- 27" DL- 262 FPS over my Garmin chrono. Swapped strings immediately to a set of GAS before it left the shop and shooting bullet holes in paper @ 3'.

My typical process is shooting daily at ranges 20-60 yards, occasionally further. The bow is grouping arrows quite well, and I am pretty happy with my form and ability this year- shooting well under archers MOA out to 60.

My typical process is once I'm settled and happy with pin locations, I will shoot a bare shaft with my FP's and make micro adjustments to the rest until they group together. No rest adjustments were needed, and my bare shafts are slapping shafts with my fletched out to 40 currently.

In the past, once I have bare shaft hitting with fletched, I will screw on an Iron Will or EVO head and they will fly with my FP's dead nuts. I am not having such luck. I'm seeing BH's impacting approximately 4- inches right and an inch high of my FP's. Have I just been lucky with my last 4 bows, or is something else going on?

I intend to shoot it through paper again today as the strings may have settled some to check prior to moving the rest.

 

[DB29]

Are you shooting the same 1 BH arrow or you have several different BH arrows that are all not grouping with FPs?

 

[sndmn11]

What shin color and thickness orientation do you see top and bottom?

 

[Skerhunter]

Add another arrow/broadhead and confirm both are high and right. Then finish tuning your bow. Quit wasting your time shooting paper.

 

[Beendare]

Simple, you are underspined or your bow is not BH tuned.

 

[Bump79]

I've had this happen to me before & weak arrow spine was the issue. Bareshaft for me is a starting point for broadhead tuning then I micro adjust from there. As long as spine is correct, in time, etc.

A few quick and easy things to do:

1. First thing I'd do is just check where your center shot is now. Mark your rest & take pics. Then check where the shims are. Gives you an idea of where you're at before any changes.
2. Then I'd check if you getting any vane contact with the 4 fletch. This can bugger you up quick.
3. I'm not familiar with the RX8 but you're getting great speed with a 480 grain arrow at that draw so I imagine it's a more aggressive cam. Right is potentially indicating weak spine.
   1. Easiest test is to either take a turn out of your limb bolts and see if they come together, or put on a 100 grain point and broadhead see if they come together. If they come together there's at least part of the problem. If not move on.
   2. What weight HIT do you have installed? What weight of collar do you have on? How long is your arrow shaft? Point weight will weaken the spine.
   3. If this is the issue - Maybe reduce point weight, reduce draw weight, shorten the shaft as much as you can to stiffen or consider a new 300 spine arrow.
4. Since you've marked the rest already - move it to the right and see what happens. You can move it back. A broadhead tells the story more in my opinion than the bareshaft.

 

[doc holiday13]

start with timing. Also depends on how old your strings are. they could be approaching end of life

 

[Bump79]

start with timing. Also depends on how old your strings are. they could be approaching end of life

Well I'd hope strings aren't it. He put new GAS strings on as soon as he bought it.

 

[doc holiday13]

Well I'd hope strings aren't it. He put new GAS strings on as soon as he bought it.

It could also be the strings have finally settled in and he needs to add or subtract a twist

 

[Bump79]

It could also be the strings have finally settled in and he needs to add or subtract a twist

Agreed.

 

[CCooper]

Are you shooting the same 1 BH arrow or you have several different BH arrows that are all not grouping with FPs?

Several different arrows and several different broadheads.

 

[CCooper]

What shin color and thickness orientation do you see top and bottom?

I had a red on top silver on bottom- silver on both now.

 

[CCooper]

I've had this happen to me before & weak arrow spine was the issue. Bareshaft for me is a starting point for broadhead tuning then I micro adjust from there. As long as spine is correct, in time, etc.

A few quick and easy things to do:

1. First thing I'd do is just check where your center shot is now. Mark your rest & take pics. Then check where the shims are. Gives you an idea of where you're at before any changes.
2. Then I'd check if you getting any vane contact with the 4 fletch. This can bugger you up quick.
3. I'm not familiar with the RX8 but you're getting great speed with a 480 grain arrow at that draw so I imagine it's a more aggressive cam. Right is potentially indicating weak spine.
   1. Easiest test is to either take a turn out of your limb bolts and see if they come together, or put on a 100 grain point and broadhead see if they come together. If they come together there's at least part of the problem. If not move on.
   2. What weight HIT do you have installed? What weight of collar do you have on? How long is your arrow shaft? Point weight will weaken the spine.
   3. If this is the issue - Maybe reduce point weight, reduce draw weight, shorten the shaft as much as you can to stiffen or consider a new 300 spine arrow.
4. Since you've marked the rest already - move it to the right and see what happens. You can move it back. A broadhead tells the story more in my opinion than the bareshaft.

@Bump79

I appreciate the thoughtful response.

I confirmed with the shop that built the arrows today that I am not underspined per the manufacturers chart for my parameters.

I also confirmed I am not getting fletching contact.

I have plenty of 300 spine arrows, one of which I shot last night with the same results.

I took the bow to the shop this morning and confirmed it was out of tune. It was shooting both bareshaft and fletched arrows with a left or right tear- I don't remember which. swapped the upper shim and is shooting bullet holes with both the bareshaft and fletched now.

I will shoot broadheads tonight and report back. I personally feel better chasing my broadheads with the rest now that I have confirmed everything is somewhat in tune.

 

[CCooper]

I appreciate all the responses, but no one has really answered my original question. Is it abnormal to see fletched arrows and bareshafts shoot tight groups together followed by poor broadhead flight if spined correctly? This is the first time that has happened to me, although I'm certainly not as seasoned as some with archery equipment. This will make the 5th bow I've setup in my lifetime.

 

[sndmn11]

I had a red on top silver on bottom- silver on both now.

Which side is fat/skinny for top and bottom?

 

[DB29]

Yes, it is abnormal. If your bareshafts are grouping with FPs out to 40yds and have close to the same angle of entry, then I find BHs are very close to being in tune and it should only take minor rest adjustments to finish BH tuning.

I have seen bareshafts “group” with FPs at 40yds but the bareshaft had a dramatically different entry angle. In these cases the bow was not in tune and needed cable adjustments.

 

[CCooper]

Which side is fat/skinny for top and bottom?

fat side left top and bottom now- I didn't pay attention prior.

 

[Bump79]

I appreciate all the responses, but no one has really answered my original question. Is it abnormal to see fletched arrows and bareshafts shoot tight groups together followed by poor broadhead flight if spined correctly? This is the first time that has happened to me, although I'm certainly not as seasoned as some with archery equipment. This will make the 5th bow I've setup in my lifetime.

I've done it several times but like I said it was spine or vane contact related. Or not enough vane for a broadhead. I'm glad your shop fixed you up!

My experience is that broadhead tuning is less forgiving generally than bareshaft. Some broadheads really show it, even Day Six or IW if they're unvented. They have a fair bit surface area even if they're high tolerance and will steer off if not perfect. A vented head or really compact head helps significantly but it's still not flying as straight as it can be.

Here's what I do - not that it's gospel. I set get my bow setup perfectly in spec and I get bareshaft close quick in the shop at 15. Then I just skip to broadheads and tune it out walking back in distance. I've actually been playing around with tuning with a much less forgiving head with a lot of area than what I hunt with. Say a Tooth XL Solid or VPA solid. Then hunting with a more forgiving head with less surface area. This likely is the fine tuning method I'll continue with as in my mind I've maximized what I can do.

Once I've done this bareshafts will still generally be on.

 

[nphunter]

Put the bare shaft away, adjust your rest a tiny bit until they hit together and then enjoy shooting a well tuned bow. The whole point of bareshaft tuning is to get the bow close for broadheads, broadhead flight is all that matters, if they are flying consistently then you do not have a fletching contact issue.

You're also not underspined with your setup. I'm shooting 27.5" arrows, 74lbs, 27.5" Draw and 160gr on the front and getting great results with fixed heads grouping with field points out to 80. I'm 453gr TAW and 288fps.

 

[sndmn11]

fat side left top and bottom now- I didn't pay attention prior.

Bh right is tail left. If you are fat gray on left for both then try the next shim column to the left which I think says stay gray but swap only the bottom.