Extreme FOC - wieght needed?

[kahunter]

Does anybody have any ideas how much weight it needed up front to achieve over 20% FOC?  I want to try it with my next batch of arrows, and I wondered what all I will need.  All I have is the standard 125 points right now.

I'm thinking the 100 grain inserts for sure.  I would like to use a maximum of 150 grains on the points themselves.  Will I also need the steel adaptors?  All 3 of those components would put me over 300 grains up front.

[yamapup]

What kind of arrow? How long and how much FOC do you have now?

[flatlander37]

I don't know what you're shooting, but I just set up some GT 35/55's for a hog hunt.  They are 29" long with standard inserts and 250 grain points, and if my calculations are correct I have 21.55% FOC.

[kahunter]

Sorry, I forgot to post my arrow info.  I will probably be shooting a .500 spine shaft at about 28".  I am shooting aluminum now, but will be switching to carbon on this batch.  Don't really have any FOC numbers on my current setup.

[Jason Jelinek]

GT 7595 with 100 grain inserts, 250 grain steel screw-in points gives me about 625-650 grains with 25% FOC.

GT 5575 with aluminum inserts, 250 grain steel screw-in points gives me about 525 grains with ~20% FOC.

Jason

[kahunter]

From those examples it would seem that somewhere around 250-275 up front yields @ 20% FOC.  From there every 100 grains adds 5%?  Does that sound about right?

[Gil]

It all depends on the length and weight of your shaft.
Gil

[kawika b]

what is your drawlength? been asked a couple of times already as it is important,,, everything hanging off the buisness end off the shelf will be "tip weight" and is used to factor in FOC. Goltip's FOC Calculator works pretty good.

[kahunter]

26.75" draw.  I'm not looking for specific answers just a general "rule of thumb" if you will.  I think you all have got me on the right track.  

After reading some other strings on the subject I think I will start out with the normal insert, the steel adaptors, 125 points, and then tune with shaft length and the gold tip weights I already have.  Thanks for all the replies.  

[kahunter]

I just thought I would bring this back up.  I just thought to use the FOC calculator on the Gold Tip site.  I think that was just what I needed.  Haven't built an arrow with it yet, but it looks like a great resource.  Juat thought I would let anybody know that's interested.

[LKH]

Be sure to work down in length about 1/2" at a time.  The carbons tend to be finicky to get good flight.  My experience is that they are stiffer than advertised.