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I shoot a mathews lx at 70# and have a 25 inch draw lenght. The arrows I shoot are about 360 grains. I get 240fps with this setup. With a 420grain arrow I get around 230fps. Anyway my question is this how much energy is lost in my bow with shooting such a light arrow? Also could I get the same speed with a 60# bow with the same draw lenght and the 360 grain arrow as less energy would be lost in the bow?? I hope this doesn't sound like a stupid question. Thanks
 

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70# and a 420g will shoot the same speed as 60# and a 360g. It doesnt matter how much weight you shoot, it will be the same speed if you keep it at 6g per/in like you have now. I dont know how much energy is lost but 360g is fine if your shooting whitetails.
 

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[email protected] arrow=49.3 ft/lbs KE
[email protected] arrow=46.0 ft/lbs KE

>>could I get the same speed with a 60# bow with the same draw lenght and the 360 grain arrow.

No. If a 70lb bow and 360gr arrow gets 240fps, dropping to 60lbs with the same arrow weight will net a velocity an KE loss. Maybe with a different more effecient bow/cam combo than the one you have you could get the 60lbs/240fps/360grs.
 

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a great question, with a answer that is it sure depends on what you want. I like a setup with a slower arrow speed and more peneration. So I use the regular carbons and not the super light. I also had weight to the shaft with a extra 100 gr brass insert. Why, I get that much more down range peneration. I still seem to have one pin that is sighted in for 25 yards but If I can see a deer in the woods I just have to hold on and I am good from 10 ft out thru 35 yards...I am shooting a bow with the peak weight is 62 lbs and am draw a full 29 inch...I am sure you will also get the response that what you want is the lightest, faster arrow, and you will get peneration.
 

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Well I can't tell how much KE will be lost, since I am away from my other PC and not smart enough to figure it out by myself. :tongue:
But IMO I dont think 360 is a light arrow. I hunting with arrows that weigh 317 gr and I am shooting [email protected] inches and shoot right around 260 FPS. I have no problems killing deer; if I remember 40 lbs of KE is plenty to for deer and 60lbs KE is plenty for any N.American big game.
 

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i work in a shop in fl. and all testing we have done does not support the idea that 6gr/# is 6gr/#. anytime we have tested this at 70# it is always faster than at 60#. i don't know why but it is. sometimes only a few feet some times as much as 8-10 fps.
my bow is rated at 313 fps at 60# 5 gr/# 30" draw which it actually gets 315 on a certified chrono. at 70# - 5 gr/# 30" draw it gets 320fps. i 've seen this with hoyts , martins, bowtechs, and dartons. go figure
 
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