# Epek Range



## coydogg (Oct 6, 2007)

I picked up some Epek broadheads a little while back and have been extremely impressed with them. They have fully deployed every shot. And they fly EXACTLY like my field tips out to 50 yards (thats as far as I shoot at the moment). I have a friend that enjoys the long shots and is shooting up to 140 yards. I recommended the Epeks to him because you don't ever have to practice with them and instead up beating up his broadheads, he could be practicing with field tips. I was wondering how far people have shot them and stayed accurate compared to their field tips? I highly dout they are going to be flying the same at 140 yards but what about past 70 yards?


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## SaltLakeArcher (Feb 23, 2009)

I don't see any reason they would not fly the same at all ranges. Quite honestly there are probably very few people in the world who could shoot a group consistant enough at 140 yards to be able to say for sure. Lets just hope he is not shooting at live animals from that range :shock:


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## coydogg (Oct 6, 2007)

He is shooting balloons at 140. But he did drop his deer this year at 95 yards. Which is pretty insane in my opinion. The only other guy I heard of dropping a deer at a long distance was one of the dudes that works at Humphries. I think he said it was like 114 yards. It was like 3 or 4 years ago so I dont remember exactly. I think I will stick to 60 and under.


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## Old Fudd (Nov 24, 2007)

140 yards 90 yards 80 yards. You have any idea how small the kill area is at that distance? Good lord get a muzzy tag.


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## jahan (Sep 7, 2007)

oldfudd said:


> 140 yards 90 yards 80 yards. You have any idea how small the kill area is at that distance? Good lord get a muzzy tag.


Is this a trick question, technically it is the same size, just farther away. :mrgreen: :lol: I know what you are saying, I won't shoot past 40 at an animal, but I will practice out farther.


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## coydogg (Oct 6, 2007)

Yeah I am at 40 right now. I only have 3 pins. I can shoot 50 without a pin but not that great yet. I am just going to keep my range at 40 this year and then upgrade to a new 5 pin sight next year. I dont see anything wrong with shooting animals at 60 yards. I wouldnt go further that though and I average about 75 shots a day with my bow.


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## middlefork (Nov 2, 2008)

coydogg said:


> Yeah I am at 40 right now. I only have 3 pins. I can shoot 50 without a pin but not that great yet. I am just going to keep my range at 40 this year and then upgrade to a new 5 pin sight next year. I dont see anything wrong with shooting animals at 60 yards. I wouldnt go further that though and I average about 75 shots a day with my bow.


Just learn to stack your pins and you can practice out to 70 pretty easy. It is fun to shoot long range practicing and definately make the shorter shots easier. That said my confortable max range on a critter is around 40.


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## GaryFish (Sep 7, 2007)

So back to the original question - at what range will the epek still deploy?

I'm not an archery guy so bear with me on this line of reasoning-

The real question, is how much force is required to make the epek deploy - right?

If that is known, then you can chrony the arrow speed at X distance, multiply by the weight of the arrow, and that will give you the amount of force at that particular distance, right? 

I would assert from what I know (very little ;-) ) that deployment is about force - not range.

Knowing the three key parts - arrow speed, arrow weight, and force required to deploy the head, it should be a pretty simple matrix to determine maximum distance.


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## Treehugnhuntr (Sep 7, 2007)

Good question. What kind of KE is required to fully deploy an EPEK? Greg, Scott?


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## elk22hunter (Sep 7, 2007)

Great question but Greg would be the best to answer this. I do know that in his testing and production of the head, he needed to find what pressure would cause it to open on inertia (spelling) and what would it take to keep it in until impact. He needed it to withstand 6 lbs of pressure at the take off out of the bow to not open in flight. He had an insert in a block of wood that he would screw a broadhead into as it faced upwards. There was a scale below the head to determine the weight that the head would withstand as we tried different tactics of keeping the head closed. The block had some upright rods to keep everything in place that was rested above. He would continue to add blocks to the top and measure the weight that it was holding while not deployed. Once it deployed then he would know what gradual weight was the last weight to hold it. That was benificial in obtaining very substantial data. I cant see the head not opening from simply dropping an arrow from waist level so in my mind, I cannot immagine in not having the energy needed to open at any distance. Gravity from a short distance will open it so it would be strange to think that it wont from a greater distance.
We don't push the thought of shooting animals at long distance so we become a bit tight lipped when the letters come in telling us of the distances killed. We know that the head has killed all sorts of animals from big to small at longer distances with great devastation. We don't promote it but obviously like hearing of what it will do and the accuracy involved with those shots.


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## MEEN (Jan 27, 2009)

Theoretically the arrow should have the same amount of energy no matter how far you shoot. So the KE at 10 yards is the same KE at 100 yards. Unless the shot is uphill at which point some of the KE is lost to PE.

The correct answer is that the Epek head will deploy at all distances. There is negligible loss to energy due to distance in the horizontal distance unless there is a MASSIVE headwind. You should feel confident in the head opening with the same reliability at 10,20,30.....on up to 300+ or whatever.


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## GaryFish (Sep 7, 2007)

MEEN said:


> Theoretically the arrow should have the same amount of energy no matter how far you shoot. So the KE at 10 yards is the same KE at 100 yards. Unless the shot is uphill at which point some of the KE is lost to PE.


Are you sure? I thought that force=mass X acceleration. That is how "knockdown power" is calculated with firearms. It is why in firearm ballistic charts, you see a decline in knockdown power at further distances, or lesser speeds. The arrow begins decelerating (as a result of air-friction and gravity) as soon as it leaves the string. So as the speed is drops, so does the force at that particular distance.

But from what E22 described, if the arrow has enough energy to still be flying, the head will deploy when it hits something solid. Is that right?


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## MEEN (Jan 27, 2009)

GaryFish said:


> MEEN said:
> 
> 
> > Theoretically the arrow should have the same amount of energy no matter how far you shoot. So the KE at 10 yards is the same KE at 100 yards. Unless the shot is uphill at which point some of the KE is lost to PE.
> ...


Yeah I am 100% positive. Force is mass x acceleration but that's not how knockdown power is calculated. Normally its KE or momentum. Which is .5 x mass x velocity and mass x velocity respectively. Theoretically the velocity is constant because the arrow does not lose energy in the x-direction, which is why it still has the same energy at any yardage.

In real conditions does it lose some energy? Yes. It loses it to air resistance, but that energy loss is so small it is negligible and it can be assumed to lose no energy. Unless there is a really really strong headwind.
The arrow does not decelerate because of gravity. Gravity only acts in the vertical distance so it can only cause the arrow to fall unless you are shooting on an incline. Then energy is lost to gravity at a rate of massxgravityxheight.


GaryFish said:


> But from what E22 described, if the arrow has enough energy to still be flying, the head will deploy when it hits something solid. Is that right?


Yes. The Epek head needs very little force to open. If I hold my arrow 12 inches above the ground and release it from rest it is enough energy to open the Epek head with the O-ring installed. That arrow hits the ground with 0.071 ft-lbs of energy. So as long as your arrow still has 0.071 ft-lbs of energy, then yes it will open the Epek XC3.


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## coydogg (Oct 6, 2007)

Awesome info! Thanks guys.


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