confused about efoc

[stevewills]

ok im going to try this just to see what happens..im going to try this with axis 400s cut to 30 at my 29 inch draw with 300 up front now im new to this so please explain what will happen here.will my arrows show weak if bareshafted.i mean i hear guys saying there shooting 35/55 out of a 55lbs.recurve with a hundred grain insert with a 150 grain head sounds like it would be weak to me.but im no expert just want to hear what you who use it do.oh by the way im pulling 59lbs with a bw pma2 62inch limbs if thatll help

[chopx2]

300gr including insert? Probably will be weak, but the only way to know is to try. I believe you will likely have an easier time tuning the 340 spine carbon shafts at 300gr total weight or possibly even the 300spine on those skinny arrows. They make the arrow spine act weaker because they are closer to center shot.

Unfortunately there are so many variables there are no definites until you try.

If you have the room you can build out the side plate to make it act stiffer. Also you could try regular 5/16" shafts which will still give you the 5% diameter difference between BH ferrule (true for most glue ons with adapters whether factory or self installed) and shaft diameter that improves penetration based on the Ashby studies.

[**DONOTDELETE**]

Yes, weak.

When you add weight to the front end of an arrow You're making it weaker. I do this for My woodies, it works with all shaft types. More people load up the front on carbons, to weaken them so they fly like darts from their bow(s).

This also helps with penetration. Once a arrow leaves the bow, the weight of the front end pulls the arrow to and thu the game. It is much easier to pull then to push.

[stevewills]

with all that weight would the spine really matter.like i said i know people who use 35/55 with 100 grain insertd and at least 150 grain bh out of a 55lb.bow im so confused

[Crash]

Each bow/shooter is a little different and what works for one may not work for another.  As has been mentioned, the only way to know for sure is to work up some arrows and shoot them.  I seem to need less spine than most but I didn't know that until I tried it.

[Ragnarok Forge]

Steve,

Your form, the bow set up, weight, etc... all impact which shaft to use.  I fought to find EFOC for a long time.  I got some good advice on here and found out the simple bare shaft tuning method by angle of shaft is almost useless for me to find EFOC.  I shoot a 68 inch mild R/D longbow with 55lbs at my 30 inch draw.  I am shooting 600 spine Easton Epics with 400 grains up front.  They fly like bullets with broadheads and field points.  I am using 4 fletch with 3 inch high shield cut fletching. The broadheads group as tight at the field points and fly perfect.  EFOC actually makes an arrow easier to tune when you get spine right.

I quite fiddling with bare shaft tuning since it continually told me the same thing with every shaft spine I tried.  Weak.  When I started group tuning with bare shafts and fletched shafts in the 340 spine I found out I was way stiff. After a lot of money and a lot of effort I ended up at 600 spine arrows with 400 grains up front.  I suggest you try the bare shaft to fletched shaft field point tuning method.  The upside is the last two years, once I fine tuned the field point groups my broadheads fire right into the same point of impact with no more tuning required.    

Ol Adcock's and some other sites have a great write up on fletched to bare shaft field point tuning.  Give it a read and give it a try.  I think you will be pleased with the results.

[kat]

Steve,
Like many have already said, a lot depends on the bow and the individual.  That being said; you are shooting a black widow that is cut past center, making it very tolerant of spine differences.
I am shooting a 400 deflection carbon with 300
+ up front out of a Black Widow. I am shooting 53#s @29" draw length.
I have found that I can drop down to 200 grains up front, and still keep good arrow flight, with very little stiffness affect.

[chopx2]

Originally posted by Ragnarok Forge:
Steve,

Ol Adcock's and some other sites have a great write up on fletched to bare shaft field point tuning.  Give it a read and give it a try.  I think you will be pleased with the results.

'
EXCELLENT POINT RF, I RECOMMEND THIS TUNING METHOD ALSO!

But unlike RF I tend to need very stiff shafts despite my draw being an inch shorter (29") than his.
I'm tuning a new bow that is cut to center (not center shot) and 31" .300 with 415gr total upfront is a little weak FOR ME.

Be careful cutting arrows as you can't add the length back! Less is more when you start to cut 1/4" or at most 1/2" at a time. I find length is very critical to spine with carbons, again FOR ME.

Your experience could be different.

I always make sure I can repeat the same weakness results 2 or 3 days in a row before cutting the shaft or make sure I can bring it in with lighter points first.

[kbetts]

I got lucky when i cut mine.  I started right at the length I wanted.  I did not take into affect the longer 100 grain insert and had I, my arrows probably would be a 1/4" longer.  I started with 125 field points, but unless my form and release were perfect, I could see the spine wasn't right while the arrow was in flight.  Up we went until I got to 200 plus the insert.  Haven't tried anything heavier yet cause I'd have to build new broadheads.

[chopx2]

BTW, there is a caveat in that O.L. tuning guide that can get lost the first time to read it. If you start too far off on spine you can get the opposite stiffness reaction. That is why trying to use tip weight to confirm your reading is important.

[ishoot4thrills]

Here's O.L. Adcock's write-up on arrow tuning:

 http://bowmaker.net/index2.htm

Click on the link and then click on "bow tuning".

Read it and mark it in your favorites. It's the best advice I've ever read on the subject, period.