I'm trying to determine my arrow speed I have no access to a chronograph and wanna figure out my ke. I have 70lb bow drop down to 62lbs my dl is 28.5 my arrows are 409.30 grains,now I got that number using the calculator on goldtip.com which also said my foc is 9.28%. I also wanna know the ke because I prefer mechanical over fixed.
Fine line - there is another thread on a different forum (not AT or MM) about this very topic. It hasn't gotten heated, per se, but one gentleman is adamant that KE is the perfect indicator for penetration, getting into the weeds, sorry - anyway since you're more interested in mechanicals you'll need a lot of "something" to help out, especially on longer shots. If your shots will be under 30 yds, I wouldn't worry to much. About the only thing you can do is to lighten your arrow weight to get more speed to increase your KE or increase draw weight to get more speed with your current arrow. That's about all you can do to increase KE the way you want, I think.
With your set up should be around 70-72 KE. Last season I shot a 405 gr. Arrow, with 2" Swhackers. Same DL as you but at 65lbs. Got pass throughs on all my deer. Even at 39 yards. Usually I shoot a 430gr. Arrow at 65-66lb. I have never had an issue with 2" Swhackers, but that is the only Mech. Head I will use. You will have better penetration with a heavy arrow that you will a light arrow. I just tried a lighter arrow last year to see how they did. I usually shoot around a 430gr. Which for hunting whitetail is perfect for me and my Hoyt's. Sent from my XT830C
Lightening the arrow will decrease ke,not increase it. Bows become more efficient with heavier arrows,therefore they yield more ke and momentum
Backcountry Bowhunting - Archery Calculator Every setup is different. For example. If I had the money I could shed about 20 grains off my arrows and increase speed but my KE will stay the same. You just have to play with it. BUT, I'd stay with a slightly heavier arrow. Momentum is just as important if not more important. Here is a good article to read that really touches on that subject. Momentum Beats Speed for Lethal Arrow Hits | Quality Deer Management Association
20 gr is not a very good weight to see ke variances with heavy arrows,hell,most chronographs don't read close enough to read speed within 1 fps and that makes a difference with that little of a change. Change the weight by 100 gr and the change in ke becomes noticeable.
It does when you really want to fine tune to get the perfect arrow weight to speed varience. I totally agree with you but was just trying to make a point. But yes, I totally agree. I think too many people focus on speed only. Yes speed is nice when your shooting 30 yards and less which is what most whitetail shots are at anyways but if you get to those ranges of 40+ yards having that extra arrow weight is going to help out dramatically with momentum, and also wind drift effects will be much less as well.
Thanks for all the info I'm wanting to figure things out because out west most shots are over 30 yrds but also for hog hunting as well. I'm shooting a 400 spine arrow at 62lbs and it is 409.30 grains but also been thinking of going up in pounds to 70 and going to a 340 spine at a 28.5 dl or should I go to 29 dl and a 28.5 arrow length in 340 spine and that would bring my arrow weight up. I know it was said above that my ke was around 70 which is really good, I'm looking on input so any opinons are appreciated.
I'm by all means no expert and their are definitely other guys on here that are more knowledgable in this area so hopefully they can chime in. I personally would find the appropriate draw length that fits you instead of just changing it. Even at your current setup it should be good. If you increased your arrow weight a bit more I think you would be more stable in windy conditions especially on those longer shots. I'm using an arrow that is about 20 grains less than you and when I shoot at 40 yards a slight breeze is really noticeable in accuracy. I'm also less poundage as you so you more than likely wouldn't be affected as much as I would be. Someone else please correct me if i'm wrong.
Go with a high foc arrow for hogs. An easton axis with feathers with 150 heads and 75 gr brass inserts will put you around 475 gr with factory wraps removed and yield around 22% foc. Tip the arrow with a,single bevel helix and you will blister hogs
My dl is between 28.5 and 29 and either one I have no problems with I had my arrows cut to 28.5. I asked because if I go to 29 I can still use 28.5 arrows.now I looked at going to 340 spine arrows at 9.3 gpi and with my arrows would be 434.95 grains thats with lighted nocks and nap quick fletch and 100 grain heads also I can go up to 70lbs and it would increase my speed and give me some more ke.
High foc will dramatically increase penetration as will the helix broadheads in a single bevel. You can fight poundage and all the other stuff if you want but you don't have to,just isn't necessary.
I was thinking a 400 spine axis but you will need to stay with the 28 1/2" draw and about a 27 1/2" arrow for the spine to handle the higher foc.
http://archeryreport.com/2012/01/kinetic-energy-momentum-arrows-simplified-approach/ Here, read this. Might help explain a few things, but take it with a grain of salt I guess.
Ok now about the arrows I've used the redhead envy x5 and switched to the beman ics patriot hunter, I really like the arrows beman makes.I was gonna go to a 340 spine ics they are 9.3 gpi and would increase my arrow weight but and increase my ke. That article was a good read and lots of info but I belive everyones experiences on here have far more value for me and thats why I ask...
Yep, personal experience always will. I think that's why this topic is discussed, experimented with, and debated so much. There are factors involved that can be explained, but it would take a high level of Newtonian Physics, Calculus, and other nasty's to fully illustrate what is happening. There is a certain diminishing returns where too little is too little and too much doesn't make a difference. Best solution, find the happy medium that works for your setup and gives the results you want.
