How important is FOC?

[Dubya]

How important is higher FOC weight in a hunting situation? The reason I ask this is I'm looking to get my broadheads mounted up on my wood arrows, but I don't know whether to get 160 or 190 grain. I currently shoot 160 grain field tips, and they put my total arrow weight is right around 600 grains. I figure 190s would add 30 grains up front therefore increasing the FOC. Thoughts anyone?

[Deb]

Personally, I would shoot the same weight as my field points.

[Dubya]

I was thinking about changing my field points to 190 as well, I guess I should have included that hahaha

[jerp]

I recently read Dr Ashby's study on high FOC and it's affect on penetration. He found that "extreme FOC" - defined as 18% or higher - significantly increases penetration. Basically, the less mass you have behind the center point of the arrow, the less the shaft flexes on impact - the flex of the shaft on impact impedes penetration.

[chackworth3]

I would shoot whichever flies best. FOC is good stuff and has its place but if you are hunting only deer then I would rather have an arrow that is tuned properly with your bow. FOC increases penetration and flight stability but the arrow has to be tuned properly with the increase in forward weight to get good arrow flight. The increase will weaken your arrow spine some...and. 600gr is already plenty of arrow weight...

[jerp]

I would shoot whichever flies best. FOC has its place but if you are hunting only deer then I would rather have an arrow that is tuned properly. FOC increases penetration and flight stability but the arrow has to be tuned properly with the increase in forward weight to get good arrow flight. The increase will weaken your arrow spine some...

Good point. Most arrow manufacturers recommend 12-15% FOC for hunting. But many trad shooters - especially those of us that shoot relatively low poundage - like more FOC. However, you can't just start adding tip weight because it doesn't take much to throw off your spine. When building my arrows I started with the total tip weight I wanted (250gr total - head plus insert) and worked backwards from there, first selecting the shaft then experimenting with length until I got it right.

[Limbwalker]

It's not FOC you should be worried about, but rather - as Chackworth3 says - which one tunes best. 30 grains is a big difference.

If you're not familiar with bare shaft tuning, you should be. Your arrows will tune better with one weight point or the other, and that's the one you should be using.

What most folks fail to realize is that more energy is lost due to poor arrow flight than anything else. The reason I get complete pass-thru's every year on every deer I shoot with just a 52# recurve is because my arrow flight is flawless and the broadhead is getting the maximum amount of energy from the arrow when it makes impact.

Poor arrow flight (meaning arrows that are fishtailing or arrows that require heavy fletching to "correct" their flight) imparts significantly less energy to the broadhead, losing most of their energy in flight (because of too large of fletching) or because the arrow hits at an angle.

A reasonble weight arrow, tuned well, will always out-penetrate a heavy arrow that is tuned poorly.

John

[caughtandhobble]

It's not FOC you should be worried about, but rather - as Chackworth3 says - which one tunes best. 30 grains is a big difference.

If you're not familiar with bare shaft tuning, you should be. Your arrows will tune better with one weight point or the other, and that's the one you should be using.

What most folks fail to realize is that more energy is lost due to poor arrow flight than anything else. The reason I get complete pass-thru's every year on every deer I shoot with just a 52# recurve is because my arrow flight is flawless and the broadhead is getting the maximum amount of energy from the arrow when it makes impact.

Poor arrow flight (meaning arrows that are fishtailing or arrows that require heavy fletching to "correct" their flight) imparts significantly less energy to the broadhead, losing most of their energy in flight (because of too large of fletching) or because the arrow hits at an angle.

A reasonble weight arrow, tuned well, will always out-penetrate a heavy arrow that is tuned poorly.

John

What John said is what you want to do, bare shaft tuning tells all of the story

[Dubya]

That's awesome info, thank you! The arrows I have fly pretty good, sometimes I get a fish tail or porpoise but I know it was form related. When I'm in the zone and all I'm thinking about is my spot on the target...the arrows fly like darts. I think I'll stick with 160 grains. However, I do need to bare shaft tune just to be sure I'll have some lasers.

[Limbwalker]

Without bare shaft tuning, you really can only guess what they're doing.

Just be sure to start close to the target. I start bare shaft tuning a new setup at about 10 ' and work back to 20 yards only when I know it will hit the bale.

John

[Bisch]

High FOC is a good thing, but a gazillion critters have been successfully shot with lower FOC.

I shoot fairly high FOC carbons (22%) but carbons are easy to to get the FOC high because the shafts are very light.

I really think that a good tune and good form are the two things that trump everything else. If your arrows are very well tuned and you can put them in the right place on an animal, you are going to be a successful hunter.

Bisch

[caughtandhobble]

You can put your 160 BH on an arrow and it will have the same effect as a bare shaft for tuning wood arrows or carbon for that matter. If you FP hits center and your BH hits left you need more weight up front, if it hits right your arrow is too weak. This is for a right hand shooter.

[Bisch]

You can put your 160 BH on an arrow and it will have the same effect as a bare shaft for tuning wood arrows or carbon for that matter. If you FP hits center and your BH hits left you need more weight up front, if it hits right your arrow is too weak. This is for a right hand shooter.

Also, when you are bare shaft or broadhead tuning, NEVER rely on just one shot to make a change. Shoot several arrows to make sure the results are confirmed.

Bisch

[BowBuddy]

Mines around 20% I like brass inserts or the Gold Tip weight system just started using that.

[Draco]

You don't have to bare shaft tune to get perfect arrow flight. Bare shaft tuning is a recent method of tuning, and while being very accurate, is not needed to get good flight.