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September 25th, 2005, 02:46 PM
I wish I could get more Kinetic Energy. I am shooting my Ross at about 63lbs. 26 1/2" draw and 1/2" loop 26" Maxima tipped with muzzy 90gr. according to my calculation I'm getting about 46 ft. lbs. of K.E. I know I can add arrow weight with weight tubes and I would just hate to switch my setup this late. I'm just worried that it might be a little on the low side for harvesting cleanly. Any suggestions.

September 25th, 2005, 02:50 PM
If your only concern is to add Ke (I'm not suggesting this) then you subtract weight and add speed. You get the greatest results by increasing speed.

September 25th, 2005, 03:10 PM
Ways to increase energy:

Increase draw length
Increase Draw weight
Increase arrow speed and weight

Velocity is squared in the KE formula, so it plays more to energy than increasing the arrow weight. You can increase your arrow speed with out many changes to your set up, but it will only be by small amounts. However, small changes can add up when totaled together. For example:

1. Switching to feathers instead of vanes, or switching to a lighter vane
2. Removing arrow wraps
3. Remove as much gear from the string as possible (peep, silencers, decrease the amount of serving, etc)
4. You can also play with the position of your silencers. The further out on the string you place them, the faster your set up will be, or use a smaller silencer.
5. Switch to a smaller, lighter, knock or inserts

All of these are very small things by themselves, but when totaled together can give you a minor boost in speed. You oculd tie on a piece of floss or something light in place of your peep, and align your pin to the left of it if you are really anal about conseving weight on the string.

The easiest thing to do is turn your bow up 5 pounds or figure a way to make your draw length longer. Is there any way to change your anchor point? I anchor back around the bottom of my ear at the back of my jaw. If you are anchoring at the corner of your mouth you may be able to gain an inch.

Look at your set up and see what changes you can make, no matter how small. 5 fps here 5 fps there, can add up to 20-50 fps with a few changes. It is the sum total of the change sthat causes the change, not the individual changes themselves.

September 25th, 2005, 03:16 PM
BowRegards and Ashadow315 are wrong.
You actually gain KE by increasing arrow weight. The speed you lose is not as much as the weight you gain.
Do some actual testing you two.
I used to be wrong about this just like you guys.

Your bow is limited on how much KE it can produce. The only way to get a noticeable amount of increase is to increase your draw weight or buy a new bow.

September 25th, 2005, 03:36 PM
Myk is correct for the most part. There is a sweet spot for speed and arrow weight for each and every bow out there. I am sorry, but I would say USMC that you are about maxed out if you're shooting a 60lb pull bow. Just a guess though.

You can play around with your arrow weight while chronographing your speeds and run them through the KE formula to find your bows sweet spot for efficiency.

In order to gain significant KE you usually need to pick up 10FPS while maintaining arrow weight. This usually is accomplished by 1" increase in drawlength (probably not the best idea) OR 5lbs drawweight increase. This USUALLY gives you 3 to 5 lbs increase in KE.

Moral of the story is if you want more energy...... shoot the same weight arrow faster, or shoot a heavier arrow the same speed.

Run the numbers, and let the math give you the answer. Good luck


September 25th, 2005, 03:41 PM
I could increase Draw weight, My bow will max out at 70lbs. just don't know if I could shoot it comfortably. I can pull it but holding and shooting it is another story. I'll try it though.

September 25th, 2005, 04:13 PM
You're OK for deer with what you have bro. Be confident with it & stay within you limits as far as accuracy are concerned. Happy huntin! :thumbs_up

September 25th, 2005, 04:23 PM
You are fine for deer! Just dont shoot what you cannot comfortably draw & hold. I agree with the others that say there is a" sweet spot " it is usually around the 6-8gr./lb of draw weight. I usually like 6-6.5 grains/lb.
If you dont want to change anything, then dont! You have enuff!

September 25th, 2005, 04:33 PM
I went a full turn on each limb I guess I gained somwhere about 3-4 lbs. of draw weight probably pulling about 66lbs. now and very comfortable. I just finished shooting about 24 arrows and feels pretty good. I'm still grouping so I'll see how this puts the Muzzy's in em. thanks for the input.

September 25th, 2005, 04:46 PM
I could increase Draw weight, My bow will max out at 70lbs. just don't know if I could shoot it comfortably. I can pull it but holding and shooting it is another story. I'll try it though.

Try and increase your weight... Doug Designed that cam to feel a few pounds lower. In other words, it is the smoothest cam out there... I believe it is imo... I have mine set at 76# and to every shop I have shown it to swears it is at 66#... Mike Mcgreevy from Copper John called me last night and cannot believe how smooth it is. He, Like you is used to hunting below the 70# mark... NOT ANYMORE!!!!

September 25th, 2005, 05:32 PM
You mentioned that you are shooting a 1/2 inch loop. If you are shooting a conventional caliper release you have probably limited your draw lengh by over an inch. You might want to look into a new Wildcat or Rhino release by Scott. Other good ones are the Carter TwoShot, and the Cobra R1 Green Mamba. The secret is to have a trigger forward so that your finger is in line with the loop.

I am 5'6" and I have had the same problem for a couple of years. This year I went to a seventy pound G2XL by Fred Bear, with GoldTip Pro Hunter 5575 and 100 grain Slick Tricks. I am still looking for one of the new forward trigger releases to complete my setup. I know the biggest thing you can change is the draw weight and draw length. Maybe one of these releases will help.

September 25th, 2005, 05:47 PM
I'm shooting the Truball w/ Talon Head and I removed the string so it's as short as it can go.

September 25th, 2005, 05:48 PM
I'll agree with those saying USMC had "enough" for deer. I'm not one for changing something that isn't broke. But the question was How do I increase KE.

And: why not push your limits and use your equipment to it's full potential?

USMC. That 3lbs of draw weight just bought you roughly 3 lbs of KE. Rough estimate. IF you choose to keep pushing up to max drawweight, I'd say you'll top out at about 56lbs KE....... I'll NEVER say that it can't be done with less..... 'cause there's too may animals killed every year with MUCH less energy that you have right now. On the same note, I'm a firm believer in fully utilizing your equipments potential. AS LONG AS you can use it properly.

Took me a full year to work up to being able to HUNT with my 84lb Pro 38. Now that I can easily shoot it full tilt, I don't. Not much anyway. My Brown Bear hunt is 2 years away, and I don't NEED 87lbs KE for anything else I'm hunting. As it is, I'm generating 74 to 76 lbs KE drawing only 74lbs. SHooting cut on contact heads, I shouldn't have much problem with generating exit holes! :wink:


Zen Archery
September 25th, 2005, 06:38 PM
youve got plenty of k.e. just let it be. if stick bow shooters barely pushing between 25-35 k.e. can down deer, elk, bears & caribou your fine. just remember shot placement.

i have a ghetto-fied arrow that is 28" @ 830 grains called the speer chucker but through my bow i am only getting 193 fps @ 68#@29". if you want details on how i did it pm me and ill send you pics.

September 25th, 2005, 06:56 PM
if stick bow shooters barely pushing between 25-35 k.e. can down deer, elk, bears & caribou your fine.
They are not shooting light carbon arrows.

September 25th, 2005, 07:00 PM
shooting right at 283 grain arrows that shot thru a deer!
Believe me man you are fine!

September 25th, 2005, 07:10 PM
You are already on the light end of the arrow spectrum.....heavy arrows will add some KE...I've never figured out why nearly everyone wants such light arrows. In most whitetail hunting shots are 20 yards or less....arrow speed isn't as critial and distance judging is not too tought at 20 yards and under. Shoot an arrow around 500 grains out of your set up and you'll get more KE.

September 25th, 2005, 07:56 PM

He asked how he could gain KE with out changing his set up. Changing arrow weight drastically will give more KE ,however, that also changes the set up. Making small changes to the arrow or the string to increase speed will also increase KE , without chaning the set up drastically.

I have done my homework. Speed is SQUARED in the formula, and thus has a more drastic effect on KE. For example, my rig turns about 280 fps with a 390 grain arrow. That gives right at 67.9 pounds of KE. Now if we go to the IBO specs on the bow, 350 grains at 318 we get about 78.6 pounds of KE. I have shot many arrow though many bows, and calculated KEs on them. I have changed out tons of components on my arrows to see how they effect weight, speed, and KE. Unless you make drastic changes in the arrow weight, speed will give you the most bang for the buck in the KE department. In other words, small changes in speed gives you more KE than small changes in weight. So there things you can do to an arrow to shed a little weight, or some tricks to the string to gain a few fps. These things are not major changes in the set up, as is changing arrow weight by 100 grains.

By the way, I NEVER said adding weight didn't increase KE. If you read my post you clearly saw it stated in the third row of things to do to increase KE. He asked how to do it with out altering his set up, and I explained some ways to do it with minimal changes to the set up.

September 25th, 2005, 08:53 PM
Speed is by no means the answer in any way shape or form when dealing with a low KE set up. If he can add speed without reducing arrow weight, then that is fine, but even a SLIGHT reduction in arrow weight can and will reduce KE. For example, with my set up:

406 grain arrow @ 272 fps= 67 lb. of KE

391 grain arrow @ 275 fps= 66 lb. of KE

While I may gain more speed with the lighter arrow, I lose a full pound of KE, and that is only with a 15 grain decrease, which really isn't that much.

USMCarcher, if you have a peep sight with rubber tubing, buy one without the tubing, if you have a kisser button, get rid of it, if you have silencers, trim them up a little bit to reduce weight, or get rid of them all together. If you have a brass nock, get rid of it and install a D-Loop, although I don't recommend this one this close to the season. You could kill any deer walking the planet right now with your set up, but if you can gain speed without decreasing your arrow weight, then by all means go for it, but with that light of set up, a heavier arrow is by far the better choice ;)

September 25th, 2005, 08:54 PM
i would recomend just changing to 85gr 4bld magnus stingers
my wife and daughter both shoot light weight low k e set ups and with c.o.c. broadheds and good placement they have always gotten pass thrus or at least poke the b h out the far side both shoot 353gr arrows at 210 fps
good luck mike

September 25th, 2005, 09:16 PM
If you had added some lbs to your draw, let it go...that'll put you in the 50-53ft.lbs.ke range. How far must we shoot into the ground after going thru a deer must we go?
There is just a "sweet spot" that you'll get to and that's all you are gonna get out of that setup.
A 350-grain arrow is heavy enuff.Exactly why do you need such a heavy arrow when your not loosing it in momentum cause the shot distance is not that far!

September 25th, 2005, 09:29 PM
I realize it's also a preference thing. I have friends who rifle hunt with a 30.06 and others who hunt with a 22-250. That is a world of difference in size of bullet but each is capable of doing the job well.

September 25th, 2005, 09:49 PM
The ONLY way he will increase KE enough to notice is to increase his draw weight. He can mess with arrow weight and any thing else he wants and it's not going to increase it noticeably.

Yes, changing speed is just as drastic as any other change that we are talking about and you're still not going to get enough speed to make a big difference.

Yes, speed is squared. Now go out and do some real homework with real arrows, a real bow and a real chronograph.
IBO specs are not real life. I highly doubt if you can get a 10ft/lb increase out of your bow without changing draw weight.
I'm talking realistically. You're not going hunting without a peep, with no fletching, no serving and every other trick they use to get their IBO speeds up.

Here is a realistic chart I figured for one of my bows using some actual arrow weights and chronograph readings at the same draw weight,
Kinetic energy
600(220x220)=29040000/450240=64.50 (-.12)
550(230x230)=29095000/450240=64.62 (+.65)
500(240x240)=28800000/450240=63.97 (+1.5)
450(250x250)=28125000/450240=62.47 (+2.41)
400(260x260)=27040000/450240=60.06 (+3.39)

Faster from lightening the arrows does not get you more KE. And the bows are limited to how much KE they produce and there is a sweet spot between too light and too heavy.

In your post you suggested "Switching to feathers instead of vanes, or switching to a lighter vane", "Removing arrow wraps" and "Switch to a smaller, lighter, knock or inserts". Those things are making the arrow lighter and will net you less KE, not more.

September 25th, 2005, 10:12 PM
Everything the same except for increasing draw poundage to max 70lbs. advertised now Stopwatch is getting 76lbs out of his 70lb draw ROSS. With that increase I would say going from 62-63Lbs. to roughly 69-71lbs. and I can still draw and hold comfortably that speed increased from 250 w/ 323 gr. arrow to 265-270 (I don't have a Chrono) w/ that same arrow equals 50 ft. lbs. @265 and 52 ft. lbs. @ 270 again I don't have a chrono or a scale so I don't know for sure if I'm actually pulling 70 are right around and I don't know if increasing poundage will boost speed almost 20 f.p.s. I'm going to give this a try anyway. Arrow by the way is a CE maxima w/ 3-blazers 2", 4" wrap nock, insert and 90gr. point est. 323 gr.

September 25th, 2005, 10:14 PM
I my ROSS maxed out at 70lbs. is actually pulling 76lbs. it has to be the easiest 76lbs. ever.

September 25th, 2005, 10:19 PM
ahhhhh the mathematical vs. theoretical KE debate........ I love it. HA HA

The moral of the entire story is that USMC's original setup would have been "OK" for a shoot on a deer. Is it better now with 3 to 5 lbs more energy available? YES! Does he absolutely NEED that energy to kill a deer? NO. But does he have a BETTER chance at "blowing through" if he center punches ribs on BOTH SIDES? YES!

To reply to the comment of just how deep do we NEED/WANT to bury an arrow in the ground after it pokes through the animal........... I pack the punch I do, because I choose to. Even on my little 80 pound piggy, I was pushing 74lbs of energy. I don't purposely shoot an animal in the shoulder, but we all know it happens....... I'm sorry, but I do not have confidence that 46lbs of energy is going to push through that big bone and kill the animal that I have chosen to kill. I do have every bit of confidence that MY equipment will finish the job, if "stuff" happens and my arrow doesn't hit exactly where I tried my best to put it. IF I make the decision to shoot an animal, I fully intend to KILL it NOW. I want it as close as possible, so every possible ounce of energy is pushing my broadhead out the opposite side of that animal REGARDLESS of what it hits on the way through.

I don't normally pick on people for comments...... but the comment referenced above is stupid IMO. Please PM me if I offend you by saying that. I have no intention to argue in a public forum. And I will not.

USMC..... by all means shoot what you are comfortable with..... YOU CAN KILL DEER WITH WHAT YOU HAVE NOW. But I'd suggest over the year (after season) work your way up to full capacity your bow will allow. Best of luck. Mike

September 25th, 2005, 10:41 PM
Last year I increased my KE a little by only switching from a 2213 to a Carbon Arrow. I did not change my draw length or draw weight. It only increased by about 5 or 6 ft/lbs. To acheive this the increase in speed was over 20 feet per second. My KE wemt from 56 ft/lb to about 62ft/lbs.

September 25th, 2005, 11:12 PM
hence the "sweet spot"

too light an arrow will hurt KE

too heavy an arrow will hurt KE also......

that's why it's called a sweet spot...........

not trying to be a jerk here, just don't see why it's such a difficult concept.....

My apologies if this comes off as me being a smart ___