EFOC & Bareshaft Tuning with broadheads

[mand0ralen]

Hi all,

I am trying to get an EFOC setup with my new bow but the results i had today at bareshafting puzzled me.

Usually when i bareshaft i get a slight angle on the target showing that i have to make small adjustment.

But this time i got a 45 degres shaft at 8 meters, showing a very very weak shaft.

Never had a so extreme reading, so i am wondering if its related to EFOC.

Further more , when i test with a fletched Arrow (helical 5 vanes), i get good accuracy up to 30 meters …

Can the EFOC masers help me please ? is my Arrow setup so wrong ?

++M

Data:
Winwin Black Wolf + Black Wolf limbs (57@28), i draw 28
Carbon express heritage 350, cut at 30.5, standard insert + 100 grain adapter + 200 gr grizzly head, total Arrow weight 695 grain
same result between a 300 grain field point and my broadhead

[Orion]

Is the shaft hitting where you're aiming, just arriving at a 45 degree angle.  If so, it may be due to a less than perfect release.   

[katman]

Shoot the bareshaft with a 100gr field tip if you have one. It should stiffen spine a little if your weak. If so shorten shaft with the 300gr tip until flies true.

[mand0ralen]

Shoot the bareshaft with a 100gr field tip if you have one. It should stiffen spine a little if your weak. If so shorten shaft with the 300gr tip until flies true.

Yeah will try that next Week, actually i tried with a 250 field point but the reading on the target was simmilar than the 300 one.

But i think the weight gap was to small between 250 and 300 to spot the difference.

++M

[mand0ralen]

Is the shaft hitting where you're aiming, just arriving at a 45 degree angle.  If so, it may be due to a less than perfect release.   

well, bad release happens from time to time , but i shot several arrows with the same result and accuracy was good at 35 yards with fletching with instinctive shooting.

++M

[Petrichor]

The title of your thread implies you are bareshaft tuning with broadheads. This in my opinion is pointless. If you get a broadhead to fly straight without fletchings it's probably luck. Bare shaft field points only. When the groups line up with fletched shafts fletch everything then add broad heads to equation and fine tune. You should be relatively close. Broadheads will exacerbate the tuning needs of an arrow. Best to do it after your close.
D

[McDave]

Totally agree with Petrichor, if you are in fact trying to bare shaft tune with broadheads. 

If you are, in fact, bare shaft tuning with field points, I suspect you are getting a false weak.  This means that the shaft is so stiff that it is rebounding off the strike plate and deflecting to the left.  Try using a weaker shaft until you are sure you are getting a true weak, and then work up from there. Increasing the point weight does not have as much effect as using a weaker spined arrow or cutting off length.

[hickstick]

yup, as others said.  NEVER bareshaft with broadheads, you can some crazy deviations in flight...dangerous even.

I was actually bareshafting over the weekend myself as I'm trying to get as close to full length shafts to reduce my point-on/gaps.   I first started with 250gn field point and a 50 grain brass insert.  got very weak indication...(not angle of arrow to target, but actual impacting to the right of fletched by 5in or so). 


dropped to 200 and that corrected some what....then to 125.  but wanting heavier point weight went back up to 200 and and started trimming the nock end little by little...  Pic showing slightly weak slightly shortened shafts with 200gns.

ended up getting it dialed in to about 1/2in to the right of my fletched group and then fletched them up and got them mixed in with the other fletched shafts.  I have a field tip test kit arriving today that I'm going to do further microtuning with.

[oz]

I have been messing with the process that Ryan Sanpai (sp) offered on the Push.  I think it was Ryan.


Start with shafts you assume to be weak.

paper tune with fletch at a short distance.  (then tune, trim length, add weight, cut weight, whatever is indicated) repeat until happy

shoot fletched shaft and a bare shaft at 10 yards (then tune, trim length, add weight, cut weight, whatever is indicated) repeat until happy

shoot fletched shafts, bare shaft, and a fletched broadhead shaft. (then tune, trim length, add weight, cut weight, whatever is indicated) until happy

move back and continue, move back and continue.

Sounds like a lot of time but I found it works.

One thing I do is set a minimum length and a desired tip weight before I start and if I cannot end up close to those desired items, I choose a different spine shaft and start over.

For example I like a 29" shaft with at least 145 up front.

I start with a 32" shaft and 190 tips and go to work.  When shafts are getting close to the 29" length I start decreasing tip weight instead of trimming shaft.  If I cannot get short enough or remove enough weight to the front, I start over with a stiffer spined set of shafts, or visa versa

[Terry Green]

Great info!....if you search you will find over 75 topics on efoc here on Tradgang.

[SuperK]

Can you tune a carbon arrow for EFOC by just cutting it to your preferred length and trying different weight  field points until you get good arrow flight?  (As you might can tell, I don't have much experience with carbon)