Primitive Archer
Main Discussion Area => Arrows => Topic started by: Kegan on May 14, 2008, 07:00:12 pm
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I've got two questions concernning arrow weight.
The first being whether lighter arrows dictate a higher nocking point? I tried shooting 700 grain arrows out of my 80# and the point of aim was way low. So, a yesterday I was shooting with my rbother and tried one of his arrows, nocking it higher than I normally. Flew perfectly fine this time. Do you jsut mess with the nocking point when dealing with arrow weight then?
Second, what's the minimum ehtical weight for arrows? My brother and I are going to test some lighter birch dowels for arrows, but it seems they would only come out 600-650 grains. WOuld that be acceptable (provided they fly accurately)?
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HEy Kegan,
Yeah, 600 grains is plenty of arrow weight. If you think a lightweight arrow isn't lethal, read my article in the current issue of Primitive Archer. I got lethal penetration of my deer with reed arrows weighing only 313 grains. They were tipped with very small "bird points".
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Kegan, The rule of thumb for a hunting weight arrow is 10grs of arrow weight per lb of draw weight...ie, 500gr arrow for 50# bow. I would say any arrow over 500gr would be fine for hunting. Billy has proved that a lighter arrow will work but for me, it isn't worth loosing an animal because the arrow was too light.
I have not noticed any difference in spine due to nocking point but most of my bows are similar. With different bows, arrows and shooters, different brace heights preform differently. You'll have to figure out what works for you, your bow and arrow. Pat
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I shoot between 500 and 600 for my hunting arrows as far as nocking point I just adjust as needed for each set up.Like Pat most of my bows are the same so I know about where they need to be.Jut
Just a little above center works fine on most of my stuff. :)
Pappy
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but I think he is asking would 600 - 650 be ethical out of his 80# bow...
is that right kegan? I would have to say that is plenty of weight to hunt an animal but there may be considerations for the impact to the bow. I have read that light weight arrow may damage bow much like dry fire?
but regarding hunting I would guess that it is like huntin tree rat with 30-30.... just my take
dont have a clue about nock poinnt height. but my guess would be that it should remain the same even over gross variations in weight. what about spine? hum... just my guess.
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I only adjust my nock point for one thing. Straight arrow flight (no porpoising, sp). I think you could change your point of aim/impact with higher or lower nock point, but you would be risking bad arrow flight. I also don't like to switch back and fourth between heavy and light arrows as it will effect your shooting. I like arrows around 500gr and try to stick as close to that as possible. 100 grains will make alot of difference in point of impact, aim, etc. especially at longer ranges.
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Thanks for the input guys!
For the nocking point, I think it will be, as Pat and Pappy suggested, a matter of experimentation as I go. I just wondered as many of the modern fiberglass bow shooters I've seen nock rather high, and most of them are using carbon or aluminum arrows. After trying it out with my brother's arrow (700 grains) it seemed to make a big difference- in that I actually hit the target :D. Since spine affects the left/right, and weight affected up/down, I wodnered that just adjusting the arrow so the rear end was slightly higher than a heavier arrow would "compensate" or something.
As for weight, I was worrying about going under the 10 grains per pound rule of thumb- which I've come to belive was an almost requisite for traditional bows. I enjoy shooting out to 55 yards at times on targets also, but my heavier arrows land in the dirt half the time, so I was interested in trying lighter shafting (which also has the benefiet of being less work :D) for arrows. Pope and Young and Howard Hill shot lighter arrows in the 600-700 grain range which confused my further, and led to my asking here.
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With bows as heavy as you are shooting, the 10gr per # rule isn't necessary for good penetration. When dealing with folks shooting bows in the 45# to 50# draw weight for hunting they would definitely want at least 10grs per #. For hunting, all you need is about 6" to 8" pf penetration to kill the animal and even less for a heart shot. Anything beyond that is over kill(so to speak ;D) and is not necessary to kill the animal...deader. Having the arrow come through the other side will help with tracking as will a pass through shot but they are not necessary. It is more critical to have an set up that you are confident with enough to put the arrow where it needs to go at the distance you are shooting. Pat
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I like 9-11 grains per lb for all my shooting and don't change this for the type of hunting I do. Heaviness of the arrow does affect spine but the question is how much. If the weight is distributed over the entire arrow arrow the effect is less. If the weight is more upfront as in footed arrows the impact is greater. It's tough finding heavy arrows for a 80# bow. Sometimes you gotta make do. Jawge
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Thanks again guys! My mind's at ease now about testing lighter arrows. Thanks for all the help, now all I gotta do is wait until they arrive and start testing :).
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my philosophy:
powerfull bow + heavy arrow = big hole and/or dead animal
light bow+light arra = less penetration and a broadhead sliceing back and forth in the animal's chest cavity as it runs which >:D= a more than likely dead animal. ;) ;)
do yall agree?
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I wonder how much ethics comes into this (within reason).
A heavy arrow going slowly may have the same momentume when it hits as a lighter arrow going faster. Identical momentum hitting an animal may have identical effect.
A bit of testing with a chronogrph would show where lighter arrows stops working in terms of increased speed. It isn't too hard maths to work out where the sweet spot is for energy imparted to the arrow.
At failry close ranges (up to 40 yards) I have found long heavy arrows are accurate to use as well as giving great penetration.
the arrow head will have an impact ethically as well as total arrow weight. A wider head may cut wider but not so deep, a narrower head may cut deeper but not so wide.
An 80lb bow it seems should put most arrows and heads clean through a dear kind animal. of course this is only ethical if you can hit the right spot on the animal in the first place, when maybe a 40lb bow could be more ethical if more accurate?
Interesting set of compromises really. I wish we could hunt here in the UK so we could worry about this stuff as well!
Mark in England
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yeah, thanx for the headache bud. ;)
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Results of testing:
My new shafting :).
The dowels arrived last week, and I've been shooting them since. They fly well, even out to 50 yards- but require much more work from me to hit the center of the target, and I've been sick for a while now. So far, I can shoot them well out to 40 yards. They fly great out of almost all of our bows, form 50-80#. They came out (the blunts) at exactly 600 grains. They don't seem to giive up too much in terms of power, just shock. I'm sure with the narrow broadheads I like to make they will take even elk or moose sized game under 30 yards. I've found that I've also had easier accuracy at medium ranges, 20-35 yards, as the level of elevation is a "comfortable" amount, meaning it doesn't take alot of overhtinking. They are also easy and quick to make up. After culling crooked grain and fimsy spined ones (I do them by hand), cutting to length and nocking, I set them on the shelf and fletch them up whenever I gte a chance. I have a full quiver of ten perfect blunts for once! They also all fly perfectly, with little probelms with varience in spine. They are rather durable and have enough power to put blunts through a board. The only downsides I have come acorss are that they require much more perfect shooting to get long range accuracy than heavier arrows (35 yards and farther) and the blunts brak off right behind the casing after slamming into a rock or tree too many times (I've shortened five so far this way). No biggies!
Once I get a few broadheads made up, I'll post pictures :).
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If you are going to test arrows I would like to see how the speed compares with a light or heavy arrow. Most guys will acknowledge a point of diminishing return with weight. It is possible to have a 60# bow that will shoot a heavy arrow the same speed as an 80# bow. It is also possible that your bow could shoot a 800 grain arrow with almost the same speed as a 600 grain arrow. I would be curious to know what your bow does, just for curiosity sake. ;) Justin
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If you are going to test arrows I would like to see how the speed compares with a light or heavy arrow. Most guys will acknowledge a point of diminishing return with weight. It is possible to have a 60# bow that will shoot a heavy arrow the same speed as an 80# bow. It is also possible that your bow could shoot a 800 grain arrow with almost the same speed as a 600 grain arrow. I would be curious to know what your bow does, just for curiosity sake. ;) Justin
The difference in speed between 600 grains and 850 grains is almost neglible. It seems that the lighter arrows may only be a few FPS faster, if anything. Oddly enough, I had to elevate my bow about the same for them both at 50 yards. I beleive that with a longbow that bends its full length, until you begin going past the 10 gpp arrow weight, they all shoot about the same speed. Speed didn't die off until I started shooting 900+ grain arrows. I did do a test with a carbon arrow, about 400 grains or so, and found it did shoot more quickly. It also made the bow kick violenttly in hand and left me jerking my bow hand to the left upon recoil :P.
Seems the old belief that Longbows were better with heavier arrows has quite the ring of truth to it.