Estimating arrow speed with 60 lbs. bow based on IBO speed.
02-03-2004, 05:03 AM
#11
Boone & Crockett
Join Date: Feb 2003
Location: Lehigh County PA USA
Posts: 12,157
RE: Estimating arrow speed with 60 lbs. bow based on IBO speed.
wolf,
I just saw a 2004 Pat DC down at the local shop. It was a 29 inch draw-60 lb model that had a birth certificate speed of 313 fps with a 300 grain arrow. Going by the general rule of a loss of 1 fps for every 5 grains of arrow weight added that would put the speed at about 303 fps with a 350 grain arrow...give or take a fps or two.
Yes, but it varies depending on how efficient any given bow is with different arrow weights. Some bows are more efficient with heavier weight arrows..some with lighter ones. I generally use 1.75 fps instead of 2 fps as it has been a more accurate number for me and my setups in the past.
Ken,
I would guess something of at least 3-4 fps. Again, it varies depending on the model and the design of the bow.
I just saw a 2004 Pat DC down at the local shop. It was a 29 inch draw-60 lb model that had a birth certificate speed of 313 fps with a 300 grain arrow. Going by the general rule of a loss of 1 fps for every 5 grains of arrow weight added that would put the speed at about 303 fps with a 350 grain arrow...give or take a fps or two.
Is this statement true: You generally loose or gain about 2 fps. for every pound of weight that it decreased or increased?
Using a 300 gr arrow... what would be the speed difference between a 60# model w/ the limbs bottomed out.. vs a 70# model w/ the limbs backed down to the same weight as the 60#er?
I would guess something of at least 3-4 fps. Again, it varies depending on the model and the design of the bow.
02-03-2004, 11:20 AM
#12
Thread Starter
Join Date: Feb 2003
Location: Pasadena Texas USA
Posts: 186
RE: Estimating arrow speed with 60 lbs. bow based on IBO speed.
Cougar Mag, I agree completely IBO speed is very overdone. There isn't an arrow that exists, that I know of, that would be correctly spined for a 70 lbs. pull, 30" LOP, that would weigh 5gr./lbs.. I think it would be difficult to shoot a 5gr./lbs. arrow through a 70 lbs. bow at 30" LOP because it would be very underspined and wouldn't tune properly.
DaveC, (same DaveC as on Texasbowhunter.com), if so howdy fellow TBH'r. I agree with you as well that's a good idea for a speed chart. So that everyone regardless of lbs. of pull could know the speed of there particular bow. It would be much more informative for everyone than only listing one particular unrealistic setup.
It's really sad that all bow companies feel the necessity to stretch the truth (lie) to the public in order to sell there product and that the sport as a whole uses a standard of measure (IBO) to compare themselves against each other that's very unrealistic. Does an arrow exist that would be spined right at 70 lbs., 30" LOP, and 5gr./lbs.? Also why don't companies show AMO speeds anymore? Is it because we the public might see through the smoke and mirrors of marketing. Sorry if I'm venting again... I'd just like to see all archery companies use the truth in there advertising and the industry use a standard of measure to compare themselves that would be realistic, unlike IBO.
DaveC, (same DaveC as on Texasbowhunter.com), if so howdy fellow TBH'r. I agree with you as well that's a good idea for a speed chart. So that everyone regardless of lbs. of pull could know the speed of there particular bow. It would be much more informative for everyone than only listing one particular unrealistic setup.
It's really sad that all bow companies feel the necessity to stretch the truth (lie) to the public in order to sell there product and that the sport as a whole uses a standard of measure (IBO) to compare themselves against each other that's very unrealistic. Does an arrow exist that would be spined right at 70 lbs., 30" LOP, and 5gr./lbs.? Also why don't companies show AMO speeds anymore? Is it because we the public might see through the smoke and mirrors of marketing. Sorry if I'm venting again... I'd just like to see all archery companies use the truth in there advertising and the industry use a standard of measure to compare themselves that would be realistic, unlike IBO.
02-03-2004, 11:44 AM
#13
Typical Buck
Join Date: Dec 2003
Location: Greenfield, IN
Posts: 953
RE: Estimating arrow speed with 60 lbs. bow based on IBO speed.
There are several carbon arrows out there that spine correctly for 70# w/ a 30" draw that would weight 350gr...
figure a:
shaft 8gpi x 30" = 240gr
3" feathers = 9gr
nock = 13gr
75gr glue in point = 75gr
glue = 5gr (prolly less)
Total= 342gr
Arrows that weight about 8gr per inch that I found in Lancasters:
Carbon Express
CX300 8.0
CXL350 8.0
LineJammer 8.2 (.2 over)
Black Hawk
Vapor 23speed 7.5
Gold Tip
5575 8.2 (.2 over)
then there's the new ultralights.. not sure on the weight though
PSE
Carbon Force Comp Pro 300 7.8
Carbon Force Extreme 7.8
Carbon Force Dominator 8.1 (.1 over)
Carbon Tech
Cheetah 7.5
Hippo 8.3 (.3 over)
Easton
Light Speed 340 8.04
Redline 360 8.31
ACC 2-71 8.04
ACC 2-71 7.38
That's not counting any new arrows that came out this year.
figure a:
shaft 8gpi x 30" = 240gr
3" feathers = 9gr
nock = 13gr
75gr glue in point = 75gr
glue = 5gr (prolly less)
Total= 342gr
Arrows that weight about 8gr per inch that I found in Lancasters:
Carbon Express
CX300 8.0
CXL350 8.0
LineJammer 8.2 (.2 over)
Black Hawk
Vapor 23speed 7.5
Gold Tip
5575 8.2 (.2 over)
then there's the new ultralights.. not sure on the weight though
PSE
Carbon Force Comp Pro 300 7.8
Carbon Force Extreme 7.8
Carbon Force Dominator 8.1 (.1 over)
Carbon Tech
Cheetah 7.5
Hippo 8.3 (.3 over)
Easton
Light Speed 340 8.04
Redline 360 8.31
ACC 2-71 8.04
ACC 2-71 7.38
That's not counting any new arrows that came out this year.
02-03-2004, 03:42 PM
#14
Thread Starter
Join Date: Feb 2003
Location: Pasadena Texas USA
Posts: 186
RE: Estimating arrow speed with 60 lbs. bow based on IBO speed.
KBacon, I'm not saying that it's not possible to make a 350 gr. arrow that's 30 inches, it's just not very realistic. Most archers that I've seen shoot 4 inch vanes instead of 3 inch feathers, they also have an aluminum adapter that the field point or broadhead screws into and generally use 100 or 125 gr. broadheads/field points. I just think that using an arrow that's 400-425 gr. is more realistic.
02-03-2004, 04:08 PM
#15
Typical Buck
Join Date: Dec 2003
Location: Greenfield, IN
Posts: 953
RE: Estimating arrow speed with 60 lbs. bow based on IBO speed.
My 30" GoldTip 5575s weight about 400 gr w/ insert, 100gr point, and 3 4" feathers.
A 4" feather weighs maybe 1gr more than a 3". And 4" vanes average between 8-10gr per.
It's not that unrealistic... it's very common. I was mainly referring to 3D type arrow where glue in points are common place. I won't be hunting w/ an arrow that light.. For hunting I'll prolly be using a 400-450gr arrow.
A 4" feather weighs maybe 1gr more than a 3". And 4" vanes average between 8-10gr per.
It's not that unrealistic... it's very common. I was mainly referring to 3D type arrow where glue in points are common place. I won't be hunting w/ an arrow that light.. For hunting I'll prolly be using a 400-450gr arrow.
02-03-2004, 07:44 PM
#16
Nontypical Buck
Join Date: Feb 2003
Location: Crosby TX USA
Posts: 2,599
RE: Estimating arrow speed with 60 lbs. bow based on IBO speed.
wolf6151, yep= it's me!!
I wonder if there has ever been a pole done on how much the average hunting arrow weighs. A 350 grain hunting arrow seems kinda light to me.
I wonder if there has ever been a pole done on how much the average hunting arrow weighs. A 350 grain hunting arrow seems kinda light to me.
02-04-2004, 01:21 PM
#17
Nontypical Buck
Join Date: Feb 2003
Location: Middletown PA United States
Posts: 3,625
RE: Estimating arrow speed with 60 lbs. bow based on IBO speed.
Dave, since you asked I'll tell ya. My hunting arrows weight 320 grains, shot at 60lbs, 27" draw. I shoot the same weight arrow for 3D--aluminum 2212's with 50gr target tips.
02-05-2004, 09:10 AM
#18
Typical Buck
Join Date: Mar 2003
Location: Glenwood Iowa
Posts: 880
RE: Estimating arrow speed with 60 lbs. bow based on IBO speed.
IBO = 70 pounds @ 30" @ 5 grains per inch....PERIOD.
Everything else is AMO. There is no such thing as an IBO rating on a 60 pound bow.
Smoke N Mirrors, Smoke N Mirrors.
Everything else is AMO. There is no such thing as an IBO rating on a 60 pound bow.
Smoke N Mirrors, Smoke N Mirrors.
03-10-2011, 07:33 AM
#19
Spike
Join Date: Mar 2011
Posts: 2
does this seem like a rough esstimate of arrow speed?
253/450=.562 fps/gr.
450gr. - 314gr. = 136gr.
136X.562=76.432
76.432 fps +253 fps = increase in speed when switching from 450gr.
arrow to 314gr. Arrow.
Chronograph data (253 fps with 450gr. arrow) from Mathews Monster TM. 56 pound draw weight
03-18-2011, 08:48 PM
#20
Spike
Join Date: Feb 2011
Location: Wisconsin
Posts: 10
You can get an estimate from the Archery Calculator, here's a link. Hope it helps!
http://www.backcountrybowhunting.com/articles/calc/
http://www.backcountrybowhunting.com/articles/calc/