FOC and Math ( pun intended)

Crossbow Hunting

Moderator: Excalibur Marketing Dude

Post Reply
The Butcher
Posts: 198
Joined: Fri Nov 26, 2004 2:00 pm
Location: Just Outside Pittsburgh, Pa

FOC and Math ( pun intended)

Post by The Butcher »

I never was good in Math, can someone tell me what percent my Foc is with a 20-5/8" shaft, broadhead included. 19" shaft without broadhead, with a balance point at 9 inches from the tip of the broadhead. And after you figure it out, should I be shooting a lighter head, or a shorter profile head, or what to get the right FOC. As of now, I've come up with a whole $^%^%$$##$% mess. I usuall just shoot my field tips, and shoot my hunting heads until I find a quiver full that fly to the spot and quit worrying about it. I'm alway open to a better way. But my numbers ain't jiveing or is that jiving "they just ain't right" Butcher
If you always tell the truth, there is nothing to remember. Mark Twain
mikew
Posts: 257
Joined: Wed Nov 30, 2005 10:57 pm
Location: York County, PA

Post by mikew »

According to the following auto-magic calculator:
http://home.att.net/~sajackson/archery9.html

I get 6.3% if I use 20 5/8 as the arrow length.

Seems too small an FOC to me and you'd want a heavier broadhead.

Please, someone else check this too. :shock:

-Mike
Bucktail
Posts: 146
Joined: Fri Jan 14, 2005 9:55 am
Location: Southren Maryland

FOC

Post by Bucktail »

MikeC,

Iget the same answer, if I'm doing it correctly.


Butcher,

Do you have Brass inserts, or Alum? Feathers or plastic fletch?

Bucktail
The Butcher
Posts: 198
Joined: Fri Nov 26, 2004 2:00 pm
Location: Just Outside Pittsburgh, Pa

Post by The Butcher »

I have aluminum inserts. I need to get the foc to what? 12-13%? Thanks Butcher.
If you always tell the truth, there is nothing to remember. Mark Twain
mikew
Posts: 257
Joined: Wed Nov 30, 2005 10:57 pm
Location: York County, PA

Post by mikew »

Butcher,
Peoples' opinions vary, but a balance point 2 1/2" to 3" in front of center puts the F.O.C 12.1% to 14.5%, as a point of reference for your arrow/broadhead.

I think everyone agrees it should be at least 10%, if not a smidge more and I think having an FOC too high is better than one to low.

Hope that helps,
-Mike
Daniele
Posts: 203
Joined: Thu Oct 10, 2002 3:51 am
Location: St marys, sw ontario

FOC

Post by Daniele »

FOC ???? MEANING PLEASE.
Good hunting, be safe.
The Butcher
Posts: 198
Joined: Fri Nov 26, 2004 2:00 pm
Location: Just Outside Pittsburgh, Pa

Post by The Butcher »

Front Of Center
If you always tell the truth, there is nothing to remember. Mark Twain
bj
Posts: 806
Joined: Tue Oct 22, 2002 7:45 am
Location: Summerside, Prince Edward Island, Canada

Post by bj »

6.360 % foc...you should have more...

things you can do !...
- change from vanes to feathers (this will increase it"slightly")
- add 25 grains to the point weight
- add a brass insert (+65 grains) - this is the way i would go...i would probably change to an 85 grain head then to get some of the speed back...

bj........
Post Reply