how do i figure my foc. i'm shooting gold tip 35/55 full lenth with standard insert and a 200 gr. point. i have 3- 5" feathers and a long arrow rap.
also as well as i can remember my total weight is 500 gr.
Do a search in the PowWow section. There are formulas posted here that will help you figure your FOC.
Here's one formula -- Distance from nock throat to balance point of the arrow, divided by the entire shaft length (Some measure from the nock throat to back of point; some include the point in the length.) minus .5 times 100 equals F0C. There's about a 1-2% difference in FOC between the two ways of measuring total arrow length.
go here http://home.att.net/~sajackson/archery9.html
alright i used the calculator that trapperdave posted and my foc is 19.8%. is this good or bad?
That's bad if your hunting for cape buffalo. Any whitetails should have two holes with 500 gr. What poundage is behind it?
Bowmania
In terms of your question about whether your arrow's current FOC is good or bad, let me share some perspective based on experience.
A few years ago, I was hunting mulies and pronghorns in Wyoming when I was presented a sharply quartering away shot at a nice mulie buck. In order to properly place the arrow, the shot needed to enter just in front of the hind quarter and go full length through the buck's body and exit on the off-side. I took the shot with a 47# Morrison recurve, hit him right where I was looking, and the buck traveled less than 100 yards before going down for good. The FOC on that carbon arrow was 31% and the penetration was nearly full length of the body.
Another year in Wyoming I was hunting with a perfectly tuned arrow and a 48# Black Widow recurve. A fat 3pt (eastern six point) mulie buck gave me a broadside shot and I took it. The arrow struck the deer perfectly, but he didn't fall. It took a lot of hours of tracking to get a follow-up shot and finish the buck. Upon performing a post-mortem, the reason for the long tracking task was clear. While the arrow struck perfectly, the BH hit a rib and deflected backwards...precluding a double-lung hit. The arrow in this instance had a FOC of 12%.
In my experience, FOC is neither "good" nor "bad" for any given set-up, but it can contribute significantly to varying degrees of penetration. With extreme FOC arrows I have shattered bone on several occasions. With less than extreme FOC, I never have.
Claudia
i am shooting these arrows from my pronghorn lb that is 47# @ my 29" draw.