By tieing the rock to the end,you change the overall weight and aerodynamics.

I just bought a dozen Carbon Express Maxima 350's FOC design.
The rep, who I am friends with was telling me that from the factory, when set up correctly, they yield about 12-13% FOC. According to him, this is about perfect for broadhead flight.

Shane

I guess that is true, really the only way to make it effect the trajectory is to add weight. I was thinking of screwing on a 170gr tip compared to a 75gr. which would give a much higher FOC but at the same time increase the overal weight. Thanks for clearing up the misunderstanding TFOX

This stuff is just rubbish. Ideal FOC depends on the arrow length, static spine, draw length and draw weight. For one setup, it might be 7%, for another is might be 30%.

If I take an arrow with a spine of 300 and shoot it out of a typical 35 lb draw weight, I might need a tip weight of 300 grains to get proper flight. This might yield an FOC in the 30% range. If I take another arrow that has a spine of 400 and shoot it out of a 75 lb draw weight, I might need a tip weight of only 75 grains to shoot properly. It may give an FOC of only 5-6%. Hopefully, the smart hunter realizes that high FOC are forgiving with broadheads and choose shafts and tip weights accordingly.

I am running 13.1% on my arrows but a gal in our club , her dad set hers up for 16% FOC for outdoors. Gives her a lot of stability especially if she is shooting in a side wind. Also she is a world class shooter and has around 10 worlds records and 130 some national records since she has been shooting. And she is just 18 years old so I would say her dad is setting up her equipment well.

Odd, but most hunting occurs outdoors. The day most hunters realize that trying to maximize speed is detrimental for hunting, and that shooting high FOC arrows designed to shoot the heavy weights correctly, will be the day our deer population starts going down quickly.

I see what you are saying, but Carbon Express has a chart similar to eastons chart for arrow selection based upon draw weight, length. I am pretty sure they are basing this upon that chart. I don't think it applies to severely over-spined or under-spined arrows.

Shane

Does this chart have a recommended shaft for a 300 grain tip?

Charts are guidlines, not rules of what tip weight you must use. I am also not referring to anything that is over or under spined. It is becoming increasingly common to put very heavy tips on heavier than normal spined arrows, to give perfect dynamic spine, resulting in perfect flight.

The point I'm trying to make, is that any tip can be made to work. Light tips result in lower FOC, and heavy tips result in higher FOC. Higher is better for stability and penetration. Hunters should realize this. 10%-15% FOC is not ideal, at least not for many people. Those deciding that they want a 300 grain tip, will end up with a much higher FOC that is correct for their setup. At least it'll be correct if they choose the shaft spine, length, and draw weight correctly.

Dr Ashbury done a test on this very subject.

Look it up it is a very interesting read with a lot of very good info in it.

The maxima shafts , and arrow dynamics of old [dont know if they are still in production] have foc built in , if it concerns you , or you are haveing dificulty getting a good foc because of your setup , you might choose one of these shafts , feathers instead of vanes , will increase , and heavyer head weight will allso increase , both however will weaken spine .