bow speed ratings


revhard

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i try to consider myself a very good bow hunter in all aspects. but one question seems to be haunting me by not knowing.

i shoot a mathews switchback,wb, and easton epic arrows with a 28'' draw and 100 gr. tips. i chrono'ed my bow and it shot 247, 246, 247 fps.

i know there is a difference between ibo(advertised) and amo, but what exactly is it and how do they each come up wih there figures?

i feel like a retard not knowing this... dont rub it in! confused.gif

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Re: bow speed ratings

A.M.O.

Under this standard the bow being tested will have a maximum pull weight of 60lbs. The arrow will have a grain weight of 540(9 grains of arrow weight per pound of bow weight). The draw length will be set at 30 inches. The chronograph used for measuring the speed will be placed at point blank range for testing.

I.B.O.

Under this standard the bow being tested will have a maximum pull weight of 70lbs. The arrow will have a grain weight of 350(5 grains of arrow weight per pound of bow weight). The draw length will be set at 30 inches. a chronograph used for measuring the speed will be placed at point blank range for testing.

there you go.

Shoot Strong

Tony

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Re: bow speed ratings

so under those standngs, it seems as if my bow shoots fairly fast. i had a frind tell me that my bow shoots slow after i told him what it chrono'ed, and he rides me over it, but he wont get his done. and by the eye my bow seems to shoot as fast as hois does.

i appreciate it tony, thanks

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Re: bow speed ratings

Everyone thinks you have to be approaching 300 fps to be fast. But those guys think 250 fps is 300 fps. B/c 250 is what they're shooting, and because the package says 300 IBO, thats what they're telling people. But when they put it on the chrono they think something is wrong. IBO ratings are fine for comparing bows side to side in a magazine, but knock 30-50 fps off of that and thats what you'll probably see in a hunting set up.

I was shooting my new Pearson Stealth last week along side a guy that was blown out of the water by the speed. He thought I was shooting in excess of 320 fps. I said "no its about 260 fps." He was like "no way mine is shooting 300 and yours is way faster than mine." I told him "don't put it on the chrono because you'll probably cry." grin.gif I won't mention what brand he was shooting. grin.gif

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Re: bow speed ratings

ha ha .. thats kinda what i was expecting to tell you the truth. i know it wouldnt be 318-320 like they advertise, but i thought it would be faster than it is by numbers anyway. but im perfectly happy with mine. shoot fast enough, as accurate as can be, and kills a crap load of wildlife!

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Re: bow speed ratings

Personally I think the whole bow speed thing is overrated. Let's look at some numbers.

A bow that shoots 300fps will launch an arrow at 204 MPH. That means that the arrow will travel 30 yards in .30 or 3/10ths of a second.

A bow that shoots 250fps will launch an arrow at 171 MPH. Sounds like a big difference huh? What it means is that means the arrow will travel 30 yards in .36 or 36/1000ths of a second.

So in essence the arrow shot from the "slow" bow will arrive at it's destination 6/1000ths of a second later. Not much of a difference if you ask me.

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Re: bow speed ratings

[ QUOTE ]

Personally I think the whole bow speed thing is overrated. Let's look at some numbers.

A bow that shoots 300fps will launch an arrow at 204 MPH. That means that the arrow will travel 30 yards in .30 or 3/10ths of a second.

A bow that shoots 250fps will launch an arrow at 171 MPH. Sounds like a big difference huh? What it means is that means the arrow will travel 30 yards in .36 or 36/1000ths of a second.

So in essence the arrow shot from the "slow" bow will arrive at it's destination 6/1000ths of a second later. Not much of a difference if you ask me.

[/ QUOTE ]

That is not the reason for speed. The faster it is the less drop you have in flight. So if you misjudge by a yard or 2 you are still making a kill shot.

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Re: bow speed ratings

My arrows are flying at 206 feet per second through the chrono at 20 feet in front of my bow. My bow is almost dead silent and the deer don't know that the arrow is in flight until something hits them from "Out of the Blue". Last years buck didn't move until the arrow hit him. I would rather shoot slow and silent any day. Speed means nothing to me. Silence is deadly.

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Re: bow speed ratings

30" 70# '05 Mathews Switchback shooting an arrow @ 280+ fps with a 418 grain arrow.

One pin set up sighted in at 25 yards......... hold dead on from 0-30 yards and my arrow is in the vitals, either a tad high or a tad low. 40 yards I aim about 5" high and drop it right in the vitals. Haven't even bothered sighting in any of the other 3 pins yet.

Speed is definitely a good thing in the event you misjudge the distance to your target, but it would take a screw up of more than 1 yard for it to matter. I pulled the following out of a bow speed discussion over on AT. As you can see, the bow is shooting 80 fps faster, but look at the TINY difference in point of impact between the 2 arrows.........

Deer is 35 yds away, you estimate it at 30

Shooting at 270 fps you would hit 3.62" low

Shooting at 350 fps you would hit 1.84" low for a difference of 1.78"

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Re: bow speed ratings

Bottom line is your never going to get max speed out of your bow, if you not shooting a 30 inch draw.

so if a bow is rated for say 300 fps and you only have a 27 inch draw, your never ever going to get close to 300 fps.

whats really critical is that the bow fit you, its quiet and you shoot it well. anything else is icing on the cake.

Shoot Strong

Tony

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Guest Kentucky_Head_Hunters

Re: bow speed ratings

I Shoot a Mathews Ultra 2 and I have shot through two different chronos at two different places. Both times I shot an average of 312 fps with 5 shots at each chrono. I have a 29" draw and I am shooting beman ics 400 arrows with 100 grain tips at 65lb pull. I do not know what the arrow weight is right off hand, but my bow is quiet and smokin when I shoot.

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Re: bow speed ratings

[ QUOTE ]

I Shoot a Mathews Ultra 2 and I have shot through two different chronos at two different places. Both times I shot an average of 312 fps with 5 shots at each chrono. I have a 29" draw and I am shooting beman ics 400 arrows with 100 grain tips at 65lb pull. I do not know what the arrow weight is right off hand, but my bow is quiet and smokin when I shoot.

[/ QUOTE ]Those are happy chronos my friend!

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