FOC Gurus

[Lowrider]

Bow 60" recurve 46@28 my draw. Arrow 35/55 28 1/8th 50 grain brass insert,175 grain 2 blade tigershark. Total arrow weight with fletching, arrow wraps, 3 four inch feathers weighs 501 grains. Front of center figured to be 19.13. Does this sound about right for deer,hog, and Turkey?

[Gdpolk]

That sounds like it would be fairly effective to me.  It's very close to what I use on all game animals here in Arkansas.

[Friend]

FOC of 19.13% will not be a discernible contributor to penetration gains beyond the mass wt of the arrow, tuned arrow, BH type and sharpness and other penetration enhancing factors.

That arrow will work fine if well tuned.

I agree with Friend also!

Bisch

[fujimo]

x3

[highlow]

Then what FOC % WOULD make a discernible difference in penetration? I have some in the 25% area. Just curious.

[Friend]

Data driven measurable increases may be calculated  when exceeding 19%.

Have visibly identified that significant increases have been routinely observed when developing arrows with 25% EFOC. And have observed obvious significantly greater penetration in the ULTRA EFOC ranges.


Am not qualified to comment on, at what minimal FOC will exhibit readily perceived penetration gains.

[screamin]

I saw an Ashby quote somewhere the other day that mentions arrow weight comes before foc.
 
But before I saw that quote, the other day after a long shooting session, in which I can get a little sloppy, yes I should stop to avoid picking up bad habits but I didn't. Any way, I missed the target with a 30% foc 600gr arrow and hit the 3/4 plywood on the side of my foam target at 30 yards. I do this to often here lately, the weather has just been so nice lately and I do over do it. Any way, the 300gr fieldpoints on these arrows never go all the way through the plywood, just halfway.

Now I also have a setup that weighs 659grs but is only 25% foc. Well, you can guess what has happened here too, have a I mentioned the weathers been so nice      :D     well guess what, these arrows shot from the very same bow go through that 3/4 plywood every time. I was really surprised when it first happened and now, I am convinced that over 650grs has merit and probably is a bone breaker. I am so convinced of the penetration potential, that my elk arrows will weight over 650 this year.        

[Friend]

screamin...out of curiousity, what are your full specs for your 30% ULTRA EFOC arrow?

Note: It typically takes approximately 400 gns up front, in combination with a very light shaft at an abbreviated length to reach 30% Ultra EFOC at 600 gns.

[screamin]

Scott, 30" Victory VF/HV 350. 100gr insert, 300 grain head, 3 - 4" fetch, comes to 31% foc. Arrows fly straight bare shaft.

I have hit that piece of plywood quite a few times and the heads will not go through. I beat them back out with a hammer. The 665gr 25% foc arrows blow right through, consistently. Same bow, same distance.

I have a question for you so I sent you a pm.

[katman]

Screamnin, is not the 665gr above the bone threshold laid out by Dr. Ashby while the 600gr are below? My bet is that extra momentum is helping more than the extra foc on the lighter setup.

[michaelschwister]

I think that would work up to and including elk, if it is tuned.

[Friend]

The Ultra EFOC arrow designs may penetrate soft tissue similarly to much lower FOC designs which may have considerably more mass(in some cases nearly a 100 gns). FOC has not proven to be a contributor to increased penetration when encountering bone breaking thresholds if the break thru has not been established.

Have harvested a deer from frontal breast entrance...complete body length penetration...with 6-8" exit back inside thigh utilizing a 52@28 bow...an Victory VForce HV350...28.5"...4" feathers...100 gn insert...300 gn Big 3 BH...611 gn total

Note: VForce HV's have been replaced with VForce Gamers

Your own results will serve to best ground your own confidence.

[screamin]

Originally posted by katman:
Screamnin, is not the 665gr above the bone threshold laid out by Dr. Ashby while the 600gr are below? My bet is that extra momentum is helping more than the extra foc on the lighter setup.

yes, and that's why it appears in my accidental testing that first and foremost, weight is the major factor when it comes to penetration.