BroadHead Weight

[N2mywake]

What weight broadhead are you guys shooting? I'm shooting carbon express maxima blue 350's with a 100g G5 currently. That leaves my FOC at about 12.22% I'm on the fence about switching to a 125gr head to increase my KE. I really like the way I'm shooting right now out to 60 but I want to make sure my penetration is there when I need it. I shoot 70 lb draw on my Creed.

What are you guys doing?

[Swede]

I shoot 100 grain BHs. If I want more weight/KE, I run a strand of weed eater string down the arrow shaft. I haven't observed any effect on arrow accuracy after getting sighted in. Trimmer string is cheaper than new BHs or arrows.

[N2mywake]

that's a good idea. I learned recently they have an item called an arrow straw that will do the same thing but fit the inner diameter of your shaft. I need to do the math to see if overall weight would help me more than weighting the front of my arrow to increase my FOC. Honestly I fear the drop from the added frontend weight.

[Brendan]

If your arrows are stiff enough, it's better to add weight up front than along the entire shaft. More FOC helps an arrow fly better, stabilize better requiring less drag from your vanes, and penetrate better when it hits. With that said - adding point weight could give you a weak spine reaction if your arrows don't have adequate spine for your setup.

I personally run 125 gr broadheads - but some inserts (gold tip for example) allow you to run 100gr and use a tool to insert weights through the shaft and screw them into the back of your insert to beef up your FOC without needing new broadheads.

I target a finished arrow speed of 280-290 fps, and add point weight until I get there.

[BrentLaBere]

I have similar specs to Brendan. Once I went to a heavier arrow setup I had better groups. Getting a new bow that could handle a heavier arrow helped me out as well.
Shooting at 10 yards my arrow speed was around 283-284 fps. Total arrow weight of 495 grains approximately. Easton 280 FMJ deep six @ 12 grains per inch with a 125 grain head.

[>>>---WW---->]

The setup you have should be plenty good. But if you want to tinker with it, go ahead and stick a 125 gr. head on a couple of your arrows and play around with it. I think you may find that the extra 25 grains will make very little difference. At least not enough to worry about.

From your post, it sounds like your setup is working good just the way it is.

[N2mywake]

I've been very pleased with this setup so far, but as I tinker I learn more and want to make it the best I can. I need to chronograph and see where I stand.


A buddy of mine recently built a spine tester so I'm anxious to use that and refletch all my arrows to the strong side to see if I can tighten up a bit more.

[Swede]

I agree with WW on this.
At long distances heavier arrows carry KE better than lighter ones. Up close it does not matter. You can run into other problems shooting long shots, so added KE may be of no importance even there.

I disagree that adding more FOC improves arrow flight. That is only true to a very limited extent. Probably 125 gr. broadheads will work with your arrows, but will not necessarily improve your arrow flight. Years ago I purchased some Satellite BHs. I asked for 125 grains at the archery store. The dealer had six new BHs in an odd little box and I was told they were 125 gr, so I purchased them at a little discount. They flew terrible and the arrows were visibly very unstable in flight. I was using 2016 aluminum shafts with an over draw rest at the time. I put the BHs on a scale and found them to all be 165 gr. I had just wasted about $20 and had to get new Thunderheads. As mentioned increasing BH weight weakens the arrow spine, and it also can destabilize your arrow by making the BH more the steering mechanism than it should be. If your BHs are helping steer your arrow, your arrow will not be hitting where your field points do either.

[Brendan]

Up close it does not matter.

Up close it will still help with penetration - so still helpful if you ever take a very close range shot at an animal.

I disagree that adding more FOC improves arrow flight.

Actually - that's physics and aerodynamics. The further forward the center of gravity is in a projectile the more directionally stable it is and the better flight you'll get. Yes, said it above but your arrow spine has to be stiff enough to support the extra weight up front or you'll be worse off or need to go to a stiffer spine arrow too. And - as the range increases you'll get more drop for the higher FOC arrow so knowing your distance dead on gets more critical because of the trajectory. (Mostly an issue at longer ranges though)

Swede mentioned those broadheads in the odd box. My guess is one of two things - they didn't spin true / crappy design, or because you added 60 grains up front you got a weak spine reaction.

I think it's all a balance though - all said and done there are a lot of setups that will work fine, and in this case - I think 12.2% is fine. I'd only think about going up to a 125 gr if your arrow speed was over 290 fps (Faster an arrow goes, the harder it is to maintain perfect broadhead flight, especially with fixed blades).

[Swede]

Weight forward 10%-15% FOC is good. I agree we are dealing with aerodynamics. Above that somewhere close things become unstable. The Satellite broadheads were fine, but too heavy for the lite shaft and weak spine that connected to it. If a person watches an arrow shot out of a machine and filmed by a slow motion camera, you can see arrows do not fly like we normally believe. They perfect ones oscillate considerably and spine and balance are critical.
There is a good reason all manufacturers have charts for their arrows that match up with a number of factors including point weight.

[Brendan]

I hate to be nit-picking, but this statement:

Above that somewhere close things become unstable.

Is not correct. The primary issues will be spine (which we've probably beaten to death) and trajectory - although I've seen results from at least one test that basically says it's the weight increase that impacts the trajectory - not the FOC. An arrow will not become unstable as FOC goes up unless you have a spine issue, screw on a crappy broadhead, or have something else going on.

[Swede]

"...there is not a universal agreement as to what is the perfect weight balance. This is further complicated by the fact that choice of point weight is made to accommodate a number of requirements other than just balance point. The optimum point weight varies with the circumstance. For example, indoor archers use heavier points to reduce the stiffness of large diameter arrows. FITA shooters feel heavier points improve grouping and counteract wind drift. IBO shooters frequently use lighter points to increase dynamic spine and reduce overall arrow weight to achieve higher velocity.
"For hunting arrows a minimum of 10% to 15% FOC is recommended to reduce planing*." Easton Certified Arrowsmith Archery University Manual VII.
"Different weight points can be used to balance different fletching weights. Point weights are also used to fine tune dynamic spine of the arrow. As a general guideline, Easton recommends a range of 7%-9% FOC for aluminum target arrows, 9%-11% for A/C/C, and 11%-16% or more for A/C/E. All page 68 of the manual.

I agree spine is the issue here. You can make a javelin, a football, or even a soda straw fly stable, but you can't load a soda straw with 3/16" bolt on the front end and propel it out of a 60# bow and get it to fly right. In the same way a soda straw would crumble under the force, an arrow with too much FOC weight will oscillate uncontrollably." That was the issue with the Satellite broadheads. I tried, but could not get enough fletching or heavy enough fletching on the arrow to stabilize it. The set up was very inaccurate, but I did my first archery bull with it. I still have that arrow crossing the mounted antlers hanging downstairs.

* (sp. Easton's)

Anyway good discussion Brendan. You have obviously put a lot of thought into this.

[Charina]

What weight broadhead are you guys shooting?

100. However . . . I wanted high foc, so I selected my spine for, and build my arrows with 50grn inserts. That way I could plan for the high foc, but have room to move both up and down easily in point weight (e.g. 125 and 85 are readily available). I looked at the gold tip inserts with weight adjustment. Decided to pass on the additional component to come loose over time.

I'm not the least bit concerned about having additional mass up front as compared to all along the arrow length. 1. Gyroscopic stabilization fights tendencies to pitch or yaw. 2. Increased foc increases the leverage the vanes' drag have on pitch or yaw. Like Brendan said, I think people conflate the idea of pitching due to increased foc with the fact that the heavier arrow has greater mass/gravity effect, and that it comes out of the bow slower. Classic apples to oranges causing erroneous conclusions. Increase the mass of both equally, then show me the high foc drops faster at distance. I don't believe it does.

[Swede]

http://www.flexfletch.com/files/281.pdf

http://www.businessinsider.com/watch-an ... ion-2012-8

We could consider the article especially the section on FOC.
I am sorry for the bad language attached to the second clip, but it was the best video I saw of slow motion arrow flight.

[Brendan]

http://www.flexfletch.com/files/281.pdf

http://www.businessinsider.com/watch-an ... ion-2012-8

We could consider the article especially the section on FOC.
I am sorry for the bad language attached to the second clip, but it was the best video I saw of slow motion arrow flight.

I don't disagree with any of that - except I want to make sure their explanations come through clearly. Excessive arrow oscillations are due to dynamic spine, not the FOC itself (Adding point weight decreases the dynamic spine of an arrow and if your spine is not adequate - you run into problems). What I've been saying all along (Maybe poorly) is IF YOU HAVE ADEQUATE SPINE - there is no downside to higher FOC other than practicality of the setup - and arrow speed / trajectory tradeoffs.

At the same time, there are benefits in terms of needing less "Steering" from your vane (thus being more forgiving), momentum and penetration. Momentum and penetration come from both total overall arrow weight, but also a higher FOC setup is more efficient on impact and retains more momentum as it hits the animal.

But again, from a practical perspective, we're probably splitting hairs here. My mindset is always just to really try to understand what's going on from a physics and mechanical perspective, as I think it helps make better decisions. I normally shoot a 300-340 spine arrow, I also have some 250 spine arrows to allow me to shoot a lot more weight up front to be able to take advantage of the higher FOC and see what downrange trajectories actually do.

[Brendan]

Like Brendan said, I think people conflate the idea of pitching due to increased foc with the fact that the heavier arrow has greater mass/gravity effect, and that it comes out of the bow slower. Classic apples to oranges causing erroneous conclusions. Increase the mass of both equally, then show me the high foc drops faster at distance. I don't believe it does.

Side note - I saw a test on this. Two identical arrows, identical weight, shot from the same bow. One had a low FOC (<10%) another a high FOC (>20%). At long ranges there was no trajectory difference. Granted, that's only one test, but supports what you're saying...

[DBLGBL]

150 Grain VPA COC on a 300 A/C/C

2gbl

[baddaddy]

125 grain Outback single bevel.

[jmez]

I shoot 125gr VPA's. Have never even given thought to change. I've always been of the mindset that a heavier arrow is better. When I started bowhunting all that was available was 125 and up. Sometime around the early to mid 90's when the great "speed race" stared in the archery industry 100g heads started to show up and within a few years dominate the scene for a few fps.

[Trumkin the Dwarf]

I shoot 265 grain tips, on 100 grain adapters.

You ought to see how well they buck the wind, and the holes they leave!

My arrows are at 27% FOC if I recall correctly. I'm actually due to retune though. My draw has crept up to a true 32, and now my arrows are a bit weak. Time to drop a little point weight.

[Swede]

Trumpkin: At the range you shoot that old Yew wood bow, aerodynamics play no part. You don't need fletching on a spear.

[Trumkin the Dwarf]

Trumpkin: At the range you shoot that old Yew wood bow, aerodynamics play no part. You don't need fletching on a spear.

Aww, cmon Swede! I shot my bull at 27 yards!

[Swede]

Twenty-seven yards! Is that all? A good javelin thrower can throw nearly a hundred yards now. You need more practice. Of coarse that is a lot farther than I can accurately shoot too. Maybe we both need to practice. Best wishes to you and your Yew wood stick. BTW: If you need another bow come to Oregon. We have a lot of Yew wood bows still on the stump. All you need is a good knife to cut it out of the tree it hides in.

[Brendan]

Trumkin - with a setup like that you could probably high shoulder shoot an elk and watch it drop like a 300 win mag (Kidding, but jealous of the 32" draw length!)

[lamrith]

For those looking to add or adjust weight (like if you hunt in multiple states and some allow illum nocks and others do not) Depending on what arrow/insert you are running Goldtip makes a weight system that is pretty handy. pretty sure they have 5-10-20grn weights, that screw into your insert inside the arrow. Not as cheap as weedeater string, but the string does not let you improve your FOC and the weights will.

I bought mine off ebay.
https://goldtip.com/componentlanding.aspx?page=4

[CurlyTail]

If your arrows are stiff enough, it's better to add weight up front than along the entire shaft. More FOC helps an arrow fly better, stabilize better requiring less drag from your vanes, and penetrate better when it hits. With that said - adding point weight could give you a weak spine reaction if your arrows don't have adequate spine for your setup.

I personally run 125 gr broadheads - but some inserts (gold tip for example) allow you to run 100gr and use a tool to insert weights through the shaft and screw them into the back of your insert to beef up your FOC without needing new broadheads.

I target a finished arrow speed of 280-290 fps, and add point weight until I get there.

X2 right on target

[N2mywake]

I think my arrows are good. I bought some 125 grain practice heads and as soon as we get some good weather i'm going to test the drop difference out to 60 and do a few other test and go from there. I think with 100g I'm pretty good but I want to bet at my best.

[>>>---WW---->]

Most of us here are elk hunters, not target shooters. After all, elk hunting is what this website is all about.

So if you have a GOOD SHARP broadhead arrow and it hits where you are aiming at all reasonable hunting ranges, go with it. In other words, if it ain't broke, don't fix it.

If you like to tinker, that is fine. But when it comes to hunting, go with what works. You owe it to the animal you are hunting.

[Beendare]

Its funny, the high FOC fans always forget that arrow with all of that weight on the end may fly better in theory... but it has to be lauched from a bowstring. All of that excess weight on the tip works against you on the launch. There is no free lunch with arrows.

I shoot a 500 gr arrow in my compound and a 600 gr arrow in my recurve. My compound arrow is an axis 300 with the 50gr inserts and a VPA 150gr BH. I think were most guys screwup is this FOC garbage and being underspined (not good). I've shot over spine arrows for almost 20 years now and they tune great in a modern compound. It's a little tricky with the stickbows as you have to get the spine just right for perfect arrow flight.