DoeLover

I'm having a problem with my arrow flight beyond 20 yards!! Arrow looks to be flying good from 20yds and in but then beyond 20 yds it looks as if the nock end is corkscrewing to the target!! What would be the most likely cause of this?? And best solution?? I know it's difficult to troubleshoot w/o seeing the arrows fly but has anyone solved this problem before?? Here is my current setup:
Bowtech ext vft 65lbs, 27.5 in. draw.
Goldtip XT 5575 @ 28 1/4 in. 369 grain arrow
85 grain points, 3 7/8 in vanes
Whisker Biscuit B2 rest

My calculations put that at an FOC of about 7.6%

I forgot to mention that the arrow flight I described is with field points. I know I'm losing energy as the drop in my arrow from 20-25 yds is 6+ inches!! I'm currently trying all of the prescribed fix-its in my tuning guide but to no avail as of yet!! Let me know if you have any insight!! Thanks!!

BobCo19-65

How was your bow tuned?

Rack-attack

Thats not whats happening - Its flying bad from zero to twenty also. I suspect the arrow is leaving the bow nock low (much harder to see when shooting) then after twenty its swing to nock high (easier to see).

This could also give you your drop problems.

Adjust the nock and see if it helps. Paper tune to see what is going on.

Arthur P

Before you start tuning, I'd recommend switching to 3" feathers with those 85 gn tips. Get your FOC up to 10%. Part of your problem is your bow is slightly out of tune. The other part is your FOC is too low, creating an unstable arrow. Getting your arrows properly balanced will make tuning a lot easier.

DoeLover

Thanks for the input...as for the tune on my bow...it was paper tuned when bought back in April...I think I will bare shaft test it now before I do anything else. As for the FOC being too low...if I shot 100 grain heads that would put my FOC at 9.2 % and total arrow weight at 384 grain. Would that be better in your opinion?? I will try a few different things here and see what happens. Once again, thanks for your thoughts!! Keep them coming!!

Arthur P

Try going up to 100 grains tips and see what they do. One thing for sure, a dozen 100 gn tips cost less than refletching your arrows. They might run your 5575's out of their spine range though.

The reasons I suggested feathers is threefold. One: You're curing your FOC problem by removing weight from the tail end of the arrow instead of adding weight at the tip, so you'd avoid any potential spine issues from the heavier tips. Two: feathers flow through WB's easier than vanes and lose very little speed from passing through the bristles as opposed to vanes. Three: Lighter arrow weight = faster arrow.

Add the speed gains from less interference with the WB and the lighter arrow, combine that with getting the bow tuned properly, and you could be looking at as much as 8-10 fps or more.

Normally I'm all for increasing tip weight and overall arrow weight, but not in this case. In your situation, I think feathers make more sense.

DoeLover

First off I appreciate the replies!!! After looking into my arrow specs a little closer I realized I made some calculation errors...go figure!! This is my current arrow setup:
Goldtip XT 5575 @ 27 3/4 in. Total arrow weight w/ 3 vanes is 367 grains.
That gives a FOC of 8.94% (I forgot to add the 15 grain insert earlier)
Arrow velocity is approx. 277 ft/sec. which gives a KE of 62.54 ft.lbs.

So if my FOC is 8.94 instead of 7.6 could there still be a problem with that or should I disregard that variable and concentrate on some other variable?? I haven't had much time to tinker but I think I will first change nocking point and see what affect it has!! Then I think I will try and shoot some of the same arrows with feathers and see if it helps!! Oh, and I'm also going to re paper tune it this weekend!! Any other sugg. I'm all ears!! Thanks in advance!!

PABowhntr

Not to answer for Arthur but I would still think that is a bit low of an FOC. 10% is usually the recommended minimum. The closer you get to it from your current situation the better. Settling for any percentage less than 10 is just basically hurting yourself.

I can get good, consistant arrow flight out of a 9.6% FOC on my setup though I wish I was above 10. I am sure I would have even more accurate arrow flight with it but I just do not want to change my entire shaft size, point weight, etc... to do so. Going the feather route that Arthur suggested would probably be the simplest way to "fix" your problem.

ijimmy

Allthouh I dont give much thought to FOC , spine is super critical in my oppinion , I might sugest trying 125 grain tips , and checking the tune of your bow , centershot and nock point , and see if you dont benifit , oh yah and it will improve your FOC allso .

BGfisher

I'd suggest that you paper tune at several different distances, like 4', 10' and 10 yards to make sure your arrow is not cutting paper at a recovery stage. I personally like to bare shaft tune. It can be time consuming but well worth the results.

One thing I do take exception to is the arrow drop from 20 to 25 yards. Man, there ain't no way to get this with a decently tuned bow. You should be lucky to see more than about an inch at 277fps. Almost imperceptable. I think the difference is showing because of the rest and the fact that the bow is not properly tuned--the rest just magnifying the errant initial launch.

I agree with Arthur to switch to feathers and try it. They will be more forgiving than vanes, and improve your FOC. Only exception I make is that if your plan to hunt with this thing later I'd fletch with 4" vanes. If for 3D and such then 3" should be plenty good enough.