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    #16
    Originally posted by bowhuntntxn View Post
    i understand. But you are going to have to sacrifice one or the other. If you want to hit them with a sledge hammer, you will have to lose speed. If you want fast, then you will be hitting them with a framing hammer.

    If you use gold tips arrow builder you can play around with different arrow weights and lengths to get your FOC where you want it. Buy notice how heavy the total arrow weight will be, and how much slower you will be shooting.

    A 400+ grain arrow shot at just about any speed will pass through any animal you shoot with it provided you don't hit big bones. You aren't going to build an arrow to knock a deer or pig off their feet when it hits them.

    Will you please tell me what is so special about this 16%. Was it because someone told you that is what you need to be effective?
    There's nothing particularly special about 16%.
    While perusing Dr. Ashby's website tuffhead.com
    I saw this and thought it'd be cool to try and build a High FOC Arrow.

    There are a several categories of forward of center (FOC) used to describe the percentage of weight forward an arrow has.
    Normal FOC = 0 percent to 12 percent
    High FOC= 12 percent to 19 percent
    Extreme FOC =19 percent to 30 percent
    Ultra Extreme FOC = more than 30 percent

    You can hunt with confidence, knowing that the TUFFHEAD™ single bevel and three blade broadheads. TuffHead has unsurpassed penetration.

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      #17
      Originally posted by Pushbutton2 View Post
      Im shooting a 419 grain arrow
      Its 29.5" long
      My FOC is 11.4% i'd like to get it over 16. Does anyone know many more grains I need to add up front?
      the general rule of thumb is 20 grains will get you 1-2% depending on a couple of variables ( like shaft gpi and length etc...). if you have enough spine its as simple a loading up the front of the arrow or you could shed an equal amount off the rear of the arrow for similar results.

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        #18
        Ok. What that article neglects to point out is the relation of total arrow weight to FOC and spine. And without that information it is easy to think it can be achieved without sacrificing something.

        Like I have said every time, you can get a 16% FOC pretty easy but not with the current arrow you shoot, and no where near the same total arrow weight or speed.

        High or above average FOC means you have to build a heavy slow arrow. Average FOC means you can buy just about any properly spined arrow and shoot standard components and normal weight broadheads and shoot higher speeds.



        Play around with this to see what you come up with. Adding another 100 grains to the front would get you over 16% but it will under spine your arrows and get them way over your current weight. And that will slow you down.

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          #19
          Originally posted by TXBlkCld View Post
          If you want hard and fast, shoot a gun. Otherwise you'll have to pick one or the other.
          I disagree. I have a 430 grain set up with 19% and there are several bows out there that can get 300+ fps @ launch with it. don't know how much faster and harder you want than that, it can kill anything on the continent.

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            #20
            Originally posted by muddyfuzzy View Post
            I disagree. I have a 430 grain set up with 19% and there are several bows out there that can get 300+ fps @ launch with it. don't know how much faster and harder you want than that, it can kill anything on the continent.

            Yep low gpi plus no wraps plus heavy inserts equals fairly light arrow traveling at high velocities that penetrate like a train. 395gr @310fps blows a 2 blade blood runner through anything.

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              #21
              Originally posted by muddyfuzzy View Post
              I disagree. I have a 430 grain set up with 19% and there are several bows out there that can get 300+ fps @ launch with it. don't know how much faster and harder you want than that, it can kill anything on the continent.
              Sorry but 430 grains is not "heavy", thus its "hard" hitting capabilities are limited. Can it kill most anything in North America? Sure but that doesn't necessarily constitute "hard" hitting. Lets take say a 600-650 gr arrow, now that will be a hard hitting arrow. It may not be moving as fast but it will hit like a ton of bricks. In this instance, you have momentum in your favor. It goes back to the slow sledge hammer vs fast claw hammer comparison. I put it like this, would you rather be hit by a smart car doing 60 or a freight train doing 40? Now there will be some arrows in the 425-475 range that will no doubt hit good a hard but not in relation to something a full 100-200 gr heavier.

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                #22
                Originally posted by TXBlkCld View Post
                Sorry but 430 grains is not "heavy", thus its "hard" hitting capabilities are limited. Can it kill most anything in North America? Sure but that doesn't necessarily constitute "hard" hitting. Lets take say a 600-650 gr arrow, now that will be a hard hitting arrow. It may not be moving as fast but it will hit like a ton of bricks. In this instance, you have momentum in your favor. It goes back to the slow sledge hammer vs fast claw hammer comparison. I put it like this, would you rather be hit by a smart car doing 60 or a freight train doing 40? Now there will be some arrows in the 425-475 range that will no doubt hit good a hard but not in relation to something a full 100-200 gr heavier.

                Dude said "fast and hard", nothing about "heavy" reread the post. I never said 430 was heavy, I don't need a lesson in physics on arrow lethality. People are running around killing animals with arrows I built in their quivers so I fairly we'll versed On the
                subject.

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                  #23
                  I've read all the replies so far and am sorry I forgot to mention a few more details about my set up.
                  My bow is a 65# bow that's pulling 68#s.
                  My arrows are approximately 29 1/8ths inch long 340 spine.
                  Per the Beman arrow chart I'm on the bubble if 340/300 spine.
                  Per the Goldtip chart I'm in the middle of the 340 spine.
                  I'm leaning towards the Goldtips because of less GPI.
                  Giving me the option of adding more weight up front and still maintain my goal of 290 fps.
                  290 fps at 420 grains gives me 78.2? KE. I forget the Momentum off the top of my head.
                  I'm willing to sacrifice speed for more FOC.
                  But like has been mentioned already with my current setup, with a well placed shot I know I can take anything in North America.
                  I'd like more FOC. But don't have the budget or equipment ,yet, to do a lot of experimenting.

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                    #24
                    Originally posted by muddyfuzzy View Post
                    Dude said "fast and hard", nothing about "heavy" reread the post. I never said 430 was heavy, I don't need a lesson in physics on arrow lethality. People are running around killing animals with arrows I built in their quivers so I fairly we'll versed On the
                    subject.
                    Heavy being the "hard hitting" part of the equation. Sorry I didn't clarify.

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                      #25
                      FOC increase

                      If you measure true momentum a heavy arrow might win, but we as a sporting culture use KE. Ever seen a rifle round's listed as kg/m/s. Would you rather be hit by a 18 wheeler going 2mph or a marble going 1000mph. Physics confused by marketing I think has created one of the best debate topics ever.
                      Last edited by Loneaggie; 11-02-2014, 11:36 PM.

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                        #26
                        For another mind bender. Your rifle and the bullet contain the same momentum. Their KE is drastically different. Which would you rather hit your shoulder?

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                          #27
                          I'm not going to be the one that explains this well,but here it goes. Kinetic is for impact in all directions. This is not what you want for a arrow. Momentum is one direction. Foward. That is the way you want your arrow to be going. Kinetic really means nothing in archery. It's just another marketing gimmick.

                          If you think kinetic is what you have to have in archery go find you a recurve man.


                          Here's a test for you. Get a good two blade head. Something that can take a hard hit. Get you a 55 gallon still drum. Fill it full of water. Now shoot your riffle through the side of that barrel. Now shoot your arrow through the side. That will show you the difference in kinetic (all direction energy) and momentum( Foward energy)
                          Last edited by enewman; 11-03-2014, 06:43 AM.

                          Comment


                            #28
                            Originally posted by bowhuntntxn View Post
                            Ok. What that article neglects to point out is the relation of total arrow weight to FOC and spine. And without that information it is easy to think it can be achieved without sacrificing something.

                            Like I have said every time, you can get a 16% FOC pretty easy but not with the current arrow you shoot, and no where near the same total arrow weight or speed.

                            High or above average FOC means you have to build a heavy slow arrow. Average FOC means you can buy just about any properly spined arrow and shoot standard components and normal weight broadheads and shoot higher speeds.



                            Play around with this to see what you come up with. Adding another 100 grains to the front would get you over 16% but it will under spine your arrows and get them way over your current weight. And that will slow you down.
                            Go to the build your arrow on this web site and you can play with the numbers and get yourself close. Good luck.

                            Comment


                              #29
                              Originally posted by enewman View Post
                              I'm not going to be the one that explains this well,but here it goes. Kinetic is for impact in all directions. This is not what you want for a arrow. Momentum is one direction. Foward. That is the way you want your arrow to be going. Kinetic really means nothing in archery. It's just another marketing gimmick.

                              If you think kinetic is what you have to have in archery go find you a recurve man.


                              Here's a test for you. Get a good two blade head. Something that can take a hard hit. Get you a 55 gallon still drum. Fill it full of water. Now shoot your riffle through the side of that barrel. Now shoot your arrow through the side. That will show you the difference in kinetic (all direction energy) and momentum( Foward energy)
                              Question for you...

                              Can you change the kinetic energy of your bow by changing the tackle? (I'm with you about momentum / kinetic energy, this is a separate discussion study)

                              On the light end, my bow pushes a 480 grain arrow to about 290 fps. The KE is about 89. If I go with a heavier setup, I'm pushing about a 580 grain arrow to a little over 260 fps... For about 89 foot pounds. If I go up to about 630 grains, my bow will push it to a little over 250 fps... Still 89 foot pounds.

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                                #30
                                Yes you are correct with your numbers. A lot of people think when you tell them I'm shooting a 600 gn arrow they think man you got lots of kinetic. But in all reality kinetic very seldom changes more then just a little from where you would have been say at 350 gn arrow. But momentum is what gains.

                                I shot some arrows a while back. Shot a 318 gn it was 74 ke. 429 gn 78 ke. 554 gn 79 ke 603 gn 80 ke 694 gn 81 ke. So as you can see ke did not change much. But the 318 gn was .457 momentum the 694 gn was. .711. Now that is a gain.

                                So to your question. No. Not shooting same bow at same poundage.

                                Once you get your set up. What ever that ke is will be roughly the same unless you can speed up that arrow. That's more poundage
                                Last edited by enewman; 11-03-2014, 03:09 PM.

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