Ultra EFOC - How?

[Ragnarok Forge]

Richie,

I agree that 3 four inch fletch should not be needed.  I am having good luck using a four fletch with 2.5 inch feathers with my field points on arrows with 21% FOC.  I plan to try them with broadheads here shortly to see how they control the arrows.  The next step will be to try a 90 degree fletch with 2 2-inch and 2 3 inch fletching set at 75-105.  

I just ordered 2 dozen Beman ICS Bowhunter shafts to try out different set ups on to see what I can get out of them and maintain good tuning.   I am looking forward to finding out just how much I can load up the front end before I can no longer tune them properly.  Rob Distefano has some that he has loaded very heavy up front and is getting good flight out of.  

I think that someone with some math skills may need to run some numbers and tests when all of this is done to see what effect FOC has on arrow tuning, etc....

[Richie Nell]

Sounds great Clay...make sure you let us all know how your work turns out.  It certainly is great information.

What is the spine deflection on the Beman ICS you are using?

My latest custom arrow is 1020 grains with 31.2% Ultra EFOC.  Just as sure as I am writing this now...that arrow flys just like a 750-800 grain arrow out of my bow, 71@31.  I am convinced the super high FOC actually makes the arrow fly flatter than NON fOC arrows.  I was amazed. And that is with 3- 3 inch feathers and 675 grains up front.  The speed seems faster than I thought as well.  I will try to chrono it today.

Bottom line is I can tell you I have noticed a significant difference in tuning with Ultra EFOC.

[Ragnarok Forge]

Richie,

The Beman Bowhunters I ordered are 500 spine arrows.  

When you get your arrows chrono'd post the numbers on this thread if you would.  I am interested to hear what speeds you are getting.

  I have a buddy building me a heavy oask sawhorse and I plan to build an bow firing system on it so I can repeat each shot at specific draw lengths.  I should have the whole thing put together in a couple weeks.

The plan is to work on getting exact numbers on velocities that are possible with various EFOC arrows and differing string counts and materials.  I also plan to test the theory that equal weight EFOC and normal FOC arrows fly differently.  The laws of physics say otherwise. I figured I could set up the sawhorse system and bow to hit a 40 yard target and see if one arrow hits lower than the other or not.  Pretty simple to test one way or the other.

The real goal I am pursuing right now is an arrow that is 650 grains or under with 30% UEFOC, or as close as I can get.  A secondary goal is to maintain 160 fps or higher velocity. Since I shoot a 55 lb longbow, that may not be possible.  Another secondary goal is to find the string count and material type that gives the best velocity and low string and bow noise. I know these are large goals,  it seems I am on an a personal quest for information which may never end.  

Upside, it sure is fun fiddling around and finding the answers.

[Roadkill]

I built a device that centers an 1/8 drill down the center of the cedar.  Managing an  airport has enlightened me, you'd be amazed at how long drill bits can be.  Then i load the end with lead shot to weight the end w/o stiffening it.  I also had a jig to band saw a cleft in the shaft to add an oak splice, but weight vs spine didn"t work for me.  Some thoughts....

[Richie Nell]

Chrono numbers below with PSAX Widow 71-72 @ 31ish. I used 300 gr. field points (15 gr. less than broadheads) due to only target available.

1005 gr. 31% UEFOC   159 fps.

835 gr. 29% EFOC   173 fps.

I would like to know if I am just seeing things or if the Ultra and EFOC arrows fly better at equal weights.  It may be all in my head.  Let me know.

[Fletcher]

Hey Roadkill, are you using some of those 12" #30 drill bits?  PM your address and I'll send you something that works much better than shot.  1/8" dia and 35 gr/in.

[Ragnarok Forge]

Richie,

you will need to define what you think flying better is for me to answer that question.  

If you mean that the arrows are hitting in roughly the same spot when fired elevation wise.  Physics says not a chance.  The 24 fps difference in velocity alone guarantees that when aimed identically the 1005 grain arrow will hit lower.  That along with gravities effect on the arrows mass means the 1005 grain arrow will also hit lower.

Those are some awesome speeds for those arrow weights. At what distance are you noticing the arrows start to really drop off while in flight?

Thanks for posting the info, the numbers are giving me some other things to think about.

[Dave Bulla]

Richie, that 835 grain arrow doing 173fps should be a nice "compromise" arrow.  Great speed for that weight arrow.... Trajectory should "feel" like shooting about a 550gr arrow out of a low 50's poundage bow but It'll hit a heck of a lot harder!

Now, go out and try the internal footings glued in to see what sort of spine increases you can come up with so I don't have to....

[Rob DiStefano]

fwiw, i think efoc is THE way to go, here's my setup and comments ...

bow holding weight: exactly 55# @ 29", 62" t/d mohawk mild r/d longbow.

shaft: beman ics 500 venture/bowhunter shafts at 29.5" from the nock groove to the front end of the shaft tube.

back of arrow: bohning nock, chopped 4" banana lo-profile 4 fletch with only a very slight offset.

front of arrow: 125 grain wensel woodsman, 125 grain stainless steel adapter, 45 grain aluminum insert.

inside shaft tube, directly behind the alum insert: 155 grain weight tube.

total arrow weight: 665 grains (+/- 3 grains)
 
arrow foc (@ 23.3"): 30.34%

arrow gpp: 12.09

at least for me, all that added front end weight doesn't affect the dynamic spine of the arrow.  as long as my release is reasonably clean, the arrow flight is dart-like and true.  as compared to my usual 585 grain arrows, these 665 grain arrows noticeably dig in deeper to a foamy butt at 20 yards.  the added 20 yard trajectory is quite slight, and not a problem to adjust my aiming.

hope to make good use of these arrows next week on a hog hunt.

[Richie Nell]

Clay,
The arrows just seem to shoot flatter longer.  I don't know..I am beginning to think that maybe they just shoot better than I was expecting but not better than physics would say.  

Also it may be that I am used to seeing my 2317 aluminums fly instead of these skinny projectiles with such small feathers.  I will just keep this ghost of a theory under my hat until you prove it one way or another.

You just keep your research going as I conitinue to be an APSW.
(Arrow Projectile Scientist Wannabe)

Dave,
That 835 arrow (850 w/Grizzly head) shoots really flat for 20ish yards.  It does have it all...weight, FOC and speed.  It would certainly leave a mark on a good size rabbit.

But you know Dave...hand loading these custom arrows won't do much good if we can't keep up with our bows..now can they.

[wingnut]

The EFOC arrow may well be flying better because it recovers from paradocs faster and will not scrub speed flying sideways.

I'm working on arrows for Connie.  She has a short draw (25.5") and limited weight (40 @ 25.5).

I'm working with some Trad .600 carbons.  So far I can get them too fly but am not satisfied.

They are cut to 28.5 and we have been shooting 175 gr up front.

I think I'll try some 250 gr heads today and see if we can get them smoking.

I'll let you know.

Mike

[wingnut]

Well teh 250 gr showed weak.  Ran out of light.  Dropping to 200 in the morning too see where they go.

Mike

[Rob DiStefano]

mike, try the 200 front end and slip in a 5" weight tube loaded with a 40 grain nail - make sure the nail in the tube and the tube in the shaft fit *tight*.  

doing so, you might find the arrow is just as stiff as before, only 55 grains heavier.  internally footing the carbon shaft seems to negate some of the added internal tube weight.  much experimenting can be done with these weight tubes ....

[Ragnarok Forge]

Rob,

What speeds are you getting with your arrows?  

How significant do you think the stiffening effect of the internal footing with weight tubes is for your arrows.  Do you think the stiffening effect have more effect on the arrow spine than having great form and a smooth release?

Does the footing you use stengthen the arrow shaft like the oak ones that OL Adcock posted about?  

Using Axis FMJ 500 Shafts at 9.1 gpi, I am really struggling to get over 21% FOC.  With 500 spine Beman Bowhunters, I should easily hit 26% and may reach 30%.  The reasons I am using the FMJ's right now is that they are incredibly tough and easily hit the minimum weights I was looking for in my arrows.  So I would love to be able to work up some beman bowhunters with the knowledge that they will be plenty tough on Elk or Wild Hogs.

[Rob DiStefano]

clay ...

i have no clue as to what actual fps speeds i'm getting outta any of my arrows ... sold off the last chrono a year or so ago.  it took me too long to realize none of that technical speed stuff matters.  when it comes to arrow speed, i use the chrono built in between my ears.  

for woods animal hunting, i'm only concerned with how the arrows fly at distances up to around 25 yards or so.  if i up the arrow weight, i need to feel comfortable with the loss of speed and increased trajectory.  going from an arrow totaling 585 grains to 665 grains wasn't a big deal for me to get used to at even 32 yards, let alone 15 yards.

after shooting 155 grain 5" weight tube arrows a whole bunch (into a foam butt with field points, and roving around with judo heads), i don't think spine is compromised at all, and may even be increased a tad.  here's the important caveat: FOR ME (not you or anyone else).

i think adding most anything internally to the arrow shaft, behind the head, will strengthen that area of the arrow.  hey, it's a 'footing' of sorts.

there is NO SUBSTITUTEfor a smooth release and a good 'hunting form'.  

if yer nagged by release/form issues, and you wanna up the foc, add in a full length unweighted weight tube to stiffen up the arrow spine, or go up to the next size stiffer shaft to accommodate yer newly added front end foc weight.    

i want to use a carbon shaft that will allow me to concentrate a LOT of weight at the forward end, yet still allow the total arrow weight to yield a good gpp for my bow's holding weight.  for me, the beman ics 500's offer good tweakability, are pretty darned durable and are bottom feeder cheap.  

a 665 grain arrow is 12 gpp for a 55# holding draw weight.  that's the kinda numbers i like for tough critters like hogs, at relatively close shooting distances.  

if the hunt was for open prairie speed goats, i'd wanna opt for a flatter shooting arrow weight of 500 to 550 grains and 9 to 10 gpp.  gosh, i'd love to kill an antelope some day ... such good bbq eatin'!

all this stuff about arrows - total weight, foc and dynamic spine - is going to be personal to each of us and we each need to put in the experimenting and testing time, IF we care to ... else, don't bother and just shoot what ya got.  all depends on yer wants and needs.

a somewhat related note: the new tbm features an article on the 'flemish 2 finger' string grip, as opposed to the more standard mediterranean 3 finger string grip.  basically, that's what i use.  the ring finger of my string hand pretty much just goes along for the ride, just touches the string and almost all of the string's holding weight is on my middle finger.  this is much closer to using a release aid and helps me achieve a much cleaner release, specially when hunting in nasty venues and weather, and my form is suffering.

[wingnut]

Rob,

Don't have any weight tubes for these smaller diameter arrows.  Rusty gave Connie these .600 and they are different then any shafts I've had before. Was thinking about checking out Home Depot this morning and seeing what I can find in plastic tubing.

Mike

[Rob DiStefano]

mike,

really small id, eh?  when i was looking around for what kinda tube would fit the beman ics, i found some plastic soda straws that had too small an od - might work for ya?  aquarium tubing?  

the carbon express 3 grains per inch tubing i'm using is a good fit for the bemans, but still needs a full wrap of blue 3m masking tape for a *snug* fit when ramming the tube deep into the shaft.  dittos for wrapping the 16d nail, for a tight fit into the weight tube.  

can't stress enuf the need for a *tight* fit of all the components of a weighted front end tube.

good luck!  you'll find something, for sure!

r.

[SlowBowinMO]

Mike the 5/16" brass tubing found at hobby stores will probably slip right over them for an external footing and point weight boost.  That's what I use on our Predator II 20/40's and 30/50's, just epoxy them on.  Make sure you've got your arrow length right before you do that, and I'd suggest you put the brass foot on before installing the insert.

[wingnut]

Well we got it!!  Went to the 200 gr point and a small nockpoint adjustment they are flying like well. . .arrows.

She's set now.

Gotta get the rest of the BHs mounted and touched up.  Going down to Gil's next weekend to get a doe or two and maybe a hog.

Thanks for the help!!

Mike

[Ragnarok Forge]

I just picked up the 2 dozen Beman ICS Bowhunters in 500 spine I ordered from my local archery shop.  I planned to make up several sets of arrows at 9, 10, 11, & 12 grains per lb for some speed and shot noise testing I am working on.  

I ran some numbers and it looks like I can set up all the arrows with 100 grain brass inserts at a full length of 30.5 inches.  I plan to use 4 - 3 inch fletch set at 75/105 and the standard nocks.  I can adjust the weights of the arrows very close to 495, 550, 605, & 660 grains by changing the heads out to 145 grains, 200 grains, 250 grains, and 300 grains.

Using the varing weight heads and running some FOC #'s The varying weight arrows for 9,10,11 & 12 grains per lb will give me

9 gr / lb - 495 gr - 19.7 %  

10 gr / lb - 550 gr - 25.3 %

11 gr / lb - 605 gr - 27.6 %

12 gr / lb - 660 gr - 29.4 %

I have to work up the basic arrows and then test them out for where they spine out right.  I am also thinking I can run outserts from aluminum arrows for external footing or work up oak dowel footings to stiffen the arrows if I need to.  Either way I have what I need to get started on the arrows.  These arrows will also allow me to run the other testing I have planned.

I will keep this thread updated as I move forward and find out what the actual foc numbers are.