Rethinking FOC

Michihunter · Post by **Michihunter** » Sun Oct 18, 2009 1:00 pm

Just recieved my November issue of Bowhunting World magazine. Interesting article on page 12 by Richard Combs titled Rethinking FOC. He explains FOC theory and how it affects penetration and long range accuracy (vertical bows) but I think the same would apply to X bows as well. I found it very informative. Just thought some of you might want to pick up the magazine and check the article out. Take care.

Michihunter · Post by **Michihunter** » Sun Oct 18, 2009 6:51 pm

Well its a fairly long article. Not sure how I could get a copy and place it on this site. I imagine someone may be able to do it. I just thought that if anyone was interested they could pickup a copy of the magazine up and give it a read. One observation I thought was interesting is that with a heavy FOC ( around 20%) the arrow actually stabilizes in a very short distance from the bow. This is a key factor in penetration as well as long range accuracy. When the arrow stabilizes quickly it enters the target (animal) much straighter giving considerably better penetration. This also allows the arrow to travel long distances with much better control giving excellant long range accuracy. There is other info in this article which I wasn't aware of. I'm sure some of you already know most of this but I didn't and found it helpful.

kennisondan · Post by **kennisondan** » Mon Oct 19, 2009 11:30 pm

that is pretty much in line with what is accepted and kicked around in bits and peices..there is not much down side to higher foc; I would think that folks were wondering if the article claimed that there was some down side other than eventually running into a coincidental spine insufficiency problem due to the foc being so far to the front coupled with insufficient thickness of the arrow shaft wall that spine would be insufficient resulting in excessive archer's paradox, I think the term is...
but that happens very little with crossbow arrows in general... they are short and spine is usually not much problem...and the higher the foc the better for the most part...I have not heard of too high foc being problematic with a crossbow arrow, ever.
dk

Michihunter · Post by **Michihunter** » Tue Oct 20, 2009 7:28 am

Ya the article basicly said the same thing that the benefits of high FOC outweighted the negatives. I probably shouldn't have posted here in regards to this article. It was just something I personally found informative and I thought others may enjoy reading about it as well. I've been bow hunting for 45 years but this crossbow thing is new to me. I'll just keep it zipped and leave the input for the more knowledgable here.

bkisel · Post by **bkisel** » Tue Oct 20, 2009 7:41 am

Michihunter wrote:Ya the article basicly said the same thing that the benefits of high FOC outweighted the negatives. I probably shouldn't have posted here in regards to this article. It was just something I personally found informative and I thought others may enjoy reading about it as well. I've been bow hunting for 45 years but this crossbow thing is new to me. I'll just keep it zipped and leave the input for the more knowledgable here.

DO NOT KEEP IT ZIPPED! I don't care that you're new to CBs, you've got 45 years of bow hunting experience, I'd be happy to read your posts and will bet that there is a lot I can learn from you.

Take care...

Cossack · Post by **Cossack** » Tue Oct 20, 2009 8:55 am

Only downside to high FOC is reduced ballistic efficiency making the arrow - esp shorter arrows like those used in CB - fall to ground sooner. That said, I'm having fewer problems with consistency of flight since switching to arrows with 18-20% FOC.

saxman · Post by **saxman** » Tue Oct 20, 2009 10:10 am

bkisel wrote:
Michihunter wrote:Ya the article basicly said the same thing that the benefits of high FOC outweighted the negatives. I probably shouldn't have posted here in regards to this article. It was just something I personally found informative and I thought others may enjoy reading about it as well. I've been bow hunting for 45 years but this crossbow thing is new to me. I'll just keep it zipped and leave the input for the more knowledgable here.
DO NOT KEEP IT ZIPPED! I don't care that you're new to CBs, you've got 45 years of bow hunting experience, I'd be happy to read your posts and will bet that there is a lot I can learn from you.

Take care...

X2
Dont zip it
Share it

bob1961 · Post by **bob1961** » Thu Oct 22, 2009 1:48 pm

i went from bout 17/18% FOC to 21.4% with a 550gr arrow and have way better flight from my arrows now....last year the deer i hit at 49 yards the arrow just blasted through it at 102fp of KE and i found my arrow 25 yards past where the deer was standing at the shot....my second deer was at 10 yards and the same thing 25 yards past the deer i found my arrow as it never slowed down as i hunt from the ground....i found a 3" hole in the hard frozen 5" deep snow, but i had to pull up the snow for 4 feet to find the vanes of my arrow under the snow....my exocet 200 is shooting those 55ogr arrows at 290fps through a chrony and only dropping off to bout 278fps at 50 yards and 15" lower....................bob

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sumner4991 · Post by **sumner4991** » Thu Oct 22, 2009 1:58 pm

bob1961 wrote:i went from bout 17/18% FOC to 21.4% with a 550gr arrow and have way better flight from my arrows now....last year the deer i hit at 49 yards the arrow just blasted through it at 102fp of KE and i found my arrow 25 yards past where the deer was standing at the shot....my second deer was at 10 yards and the same thing 25 yards past the deer i found my arrow as it never slowed down as i hunt from the ground....i found a 3" hole in the hard frozen 5" deep snow, but i had to pull up the snow for 4 feet to find the vanes of my arrow under the snow....my exocet 200 is shooting those 55ogr arrows at 290fps through a chrony and only dropping off to bout 278fps at 50 yards and 15" lower....................bob

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You need a wider broadhead, right Mike P.?