Contributors to this thread:
FOC, KE and Arrow Weight
So, I am sure this will generate lot of opinion, but that is good.. I am curious about how everyone feels about the importance of FOC? If you value KE over Momentum or visa versa? And arrow weight? I hunt out west (Elk and Mule Deer) and current set up is a GT Kinetic Kaos 465 grain arrow with 12.3% FOC and about 82lbs KE, Not sure on momentum... but I am not to crazy about a full carbon shaft.. . The reason this has come to mind for me is, I was looking at different set up options and for 2018 season, for instance if I go with the same arrow length in an FMJ, the weight comes in at around 480ish, but FOC is low around 9% range, b/c FMJ gpi is at 12.1.. Or I could go back to my Easton ACC Pro Hunters at 10.4 gpi put in a brass insert and that would be something like 475 gns/ 11.5 FOC / 82ish KE..... So I guess what is the best FOC and Arrow weight combination?
I think you're splitting hairs
FOC in the Easton recommended range [8-16%] or a little higher is a good happy medium.
I have yet to see anyone prove [even Ashby, no apples to apples data] that very high FOC in the 30%+ range has any advantage. Many guys tout the advantages...but ignore the destabilizing effect all that front end weight has on the launch.
The idea is to have a forgiving well tuned arrow. All that front end weight with EFOC arrows [or whatever Ashby calls it now] is anything but forgiving in a compound and puts guys dangerously close to being underspined in some cases. if its anything you DON'T WANT is to be underspined in a modern compound.
I think most archers are best served with a med weight arrow in the 450-550gr range and avg FOC and it seems the Easton engineers that have been testing/developing these arrows for 50 years agree.....as do 99.99% of the top shooters in all forms of archery today.
To me its a matter of,"Who do you get your advice from?" One guy touting a fringe concept or the Easton engineers and every top shooters?
if your between 10-15% FOC, your good ... arrow weight for me depends on the critter, but for deer I'm at 375grs and almost 12% foc and I stack FP's/BH's at 50 yds .. for deer I like a range of 375-400 grs maybe a tad over that ... I only shoot 62lbs, but I still get 305fps, and a MO of .51 and KE is in the high 70's ... more than enough for any deer that walks ... for elk, I'd up the weight to 425-450 and use a good COC head, the same head I now do for Deer, a Vipertrick, but a 125gr instead of a 100 gr.... but for Deer I modify the Viper with blades from a Grizztrick... for elk I'd leave the factory bleeders in ...
KE in the "high 70`s" is enough killing power for any animal in the lower 48. Back in the day of the early compounds it was a little trickier to achieve the desired KE as the bow speeds were no where near todays. So with heavier shafts you lost some speed and you had to find the optimum balance. Today it`s a little easier as most shaft/bow/broadhead weight gets it done.
Heavy foc has its advantages but as beendare stated don’t overlook your spine. The end result of too much weight forward might leave you getting stiffer shafts which will likely decrease your foc, before you know it you’re chasing your tail.
My set-ups all produce on the order of 33-38 FPE with arrows in the 400-550 grain range and 10%-15% FOC, and I have it on good authority that it would be a tremendous waste of time and energy to worry about anything other than keeping my broadheads sharp and putting them in the right place.
The heaviest rig I can really foresee shooting might give me the best part of 45 FPE.
And there are guys getting complete pass-throughs on large deer with rigs in the neighborhood of 30 FPE....
So unless you’re planning to shoot a mechanical or some idiotic design like the Toxics, I can’t imagine that you really need to sweat anything other than being well and truly tuned and taking a high-percentage shot that you know you can execute well under the circumstances.
What’s the best FOC and arrow weight combination? All depends. For someone with a 26 1/2” DL, I have to chuckle when someone wonders if their setup is sufficient with 82 KE. What I wouldn’t give! lol!
I got a bud that shoots for Elite. I got another good bud that shoots for Mathews. Both set their target setups for 12% FOC for a benefit accuracy. Not sure the results it might give for penetration is relevant with today's compounds. But, if the pro's are doing it for accuracy, there has to be a rhyme to the reason. Both say they like their hunting setup to be 15-17% though. More than that they begin to chase their tails like ohiohunter said. But, both have told me if they could get 22-25 without experiencing diminishing returns that over shadow that benefit, they'd do it. God Bless
get your arrows flying well
be able to send those arrows accurately at the distance you are comfortable with
then measure your FOC if you like knowing such statistics
end of story.
With your set-up, there is little to worry about - no reason to add arrow weight, etc.
IMO FOC is the fodder of armchair bowhunters. The best bowhunters I know couldn't even tell you what FOC is or how to calculate it.
I personally prefer an all-carbon shaft, as they will not bend like aluminum or composite shafts can.
"get your arrows flying well be able to send those arrows accurately at the distance you are comfortable with"
This. Shot a bull this past year at 27 yds with an arrow weighing 392 grs and clocked at 293 fps with 15% FOC tipped with a ST Standard and got a pass through. Elk went 50 or so yds.
KE doesn't really mean anything...
Foc increases projectile stability. Ask a feta shooter his foc and they’ll probably know off the top of their head, and I bet it’s around 20%.
It does increase penetration, but to what avail I cannot attest. IMO on the avg deer arrow 100gr, elk arrow I like to see 125+... all things being relative.
Most do not know nor knowledge foc, esp when their longest shots are 30yds on medium sized game. Your avg hunter grabs a Doz arrows and slaps 100gr bh on’m
It's FITA not feta. And those guys are shooting recurves with fingers, and never broadheads.
To keep an arrow stable, you simply have to keep the front of the arrow up front and the back of the arrow out back. It really is that simple in theory. Unfortuneately there are a number of factors that affect that in the real world. One way to "help" is to put the weight up front (FOC) . Another way to help is to put a parachute out back (fletching). Spinning the arrow in flight will aid in keeping the arrow's flight path centered in it's launch direction. Common sense and centuries of experience has taught us that we need at least two of those stabalizing factors, even in ideal conditions, but all three of them are prefered.
How much of each of those stabalizing aids is needed is a relative question. Too much of any will bring negative returns. Too much FOC creates an un-stable launch and week spine ( anything over 20% or so). Too much Fletching (think Flu-Flu arrow) will slow the arrow down way too fast. Too much spin will absorb energy needed for penetration, and also will cause the blades to enter with a scraping motion rather than a cutting motion.
Bottom line is, it's real hard to put together a bad arrow if you follow the charts and error on the stiff side. Concentrate on proper tune and accuracy.
9/10 spell check programs prefer feta
Thanks again for your input boubound. A wealth of info...
E. Donnall Thomas, editor of Traditional Bowhunter, told me once, "We sure killed a lot of animals before we ever knew what FOC and KE were".
Ashby came up with the FOC thing after shooting a few hundred critters in Africa, carefully documented the results, and compared it to non FOC. So I don't think it is fringe thinking to be compared to testing in the Easton laboratory. I usually try for around 15% because it seems like it would be an improvement and those 200+ gr BH's sure look menacing. I also have to agree with Don Thomas's comment, as for years I used whatever I could afford, and was just as happy as if I had good sense.