arrow speed

[toddjler]

I`m shooting a Mathews MR7 at 28 I/d at 69.5 #`s, my arrow weight is 458 grs, I chrono`ed it at 270 fps, giving me a calculated 74 K.E. and a.54 momentum, is this a good speed and energy level?

[LA_bowhunter]

yep. will kill any big game in North america and most in Africa (min 66 for cape buffalo I think). Would have to go up for a Giraffe or elephant though.

[L.O.S.T.Arrow]

Wasnt too long ago a 74 K.E. bow was crazy smokin!!



Neil

[Redneck Renagade]

I'm not sure of the K.E but I'm getting 340's FPS at 29 inch draw 62 lbs and 359grain arrows.

[Hydro1]

More than adequate.
Happy shooting!

[Mike_W]

Originally Posted by Redneck Renagade

I'm not sure of the K.E but I'm getting 340's FPS at 29 inch draw 62 lbs and 359grain arrows.

What bow?

[Redneck Renagade]

Originally Posted by Mike_W

What bow?

It's a 2009 PSE X-Force SS. And it's actually at 66lbs. I'm Shooting maxima 250's cut down to 27 inches which is still within specs of the arrow. Changed out factory strings to worlds best and removed all unnecessary string attachments

[normanrd]

Originally Posted by Redneck Renagade

I'm not sure of the K.E but I'm getting 340's FPS at 29 inch draw 62 lbs and 359grain arrows.

That puts you making 92.2 ft/lbs ke and your bows Ibo around 355 (based on 66# dw) Thats pretty smoking!

[Luxor]

Good speed and energy level for what?

If for hunting then you must factor in distance as well.

[58thecat]

Originally Posted by toddjler

I`m shooting a Mathews MR7 at 28 I/d at 69.5 #`s, my arrow weight is 458 grs, I chrono`ed it at 270 fps, giving me a calculated 74 K.E. and a.54 momentum, is this a good speed and energy level?

Mine is slower but equals dead from moose on down to gophers.

[backyard]

i have a DXT 27.5-70lbs and I think I chrono'ed it at 243 with 500+ grain arrows not sure what that works out too for KE energy but it would pass through moose and deer with my rpm im getting 92 for ke energey

[lgard]

Originally Posted by toddjler

I`m shooting a Mathews MR7 at 28 I/d at 69.5 #`s, my arrow weight is 458 grs, I chrono`ed it at 270 fps, giving me a calculated 74 K.E. and a.54 momentum, is this a good speed and energy level?

Shot placement is the most important thing Ted Nugent uses a 50 lb bow with non agressive cams to harvest moose in Alaska.

[brohymn2]

Originally Posted by lgard

Shot placement is the most important thing Ted Nugent uses a 50 lb bow with non agressive cams to harvest moose in Alaska.

^^^

[L.O.S.T.Arrow]

Originally Posted by lgard

Shot placement is the most important thing Ted Nugent uses a 50 lb bow with non agressive cams to harvest moose in Alaska.

Uncle Teddy must be getting old and wise too!!...lol

Neil

[toddjler]

Originally Posted by toddjler

I`m shooting a Mathews MR7 at 28 I/d at 69.5 #`s, my arrow weight is 458 grs, I chrono`ed it at 270 fps, giving me a calculated 74 K.E. and a.54 momentum, is this a good speed and energy level?

hey guys i`m back with an update, I changed my draw length to 29 inches and I dropped my arrow weight to 415 grs, the new chrono speed is 285 fps, which still gives me the same K.E. and momentum, I was thinking with the draw length and arrow weight change my speed should have come up to around 300 fps, anyone have any thoughts?

[L.O.S.T.Arrow]

Originally Posted by toddjler

hey guys i`m back with an update, I changed my draw length to 29 inches and I dropped my arrow weight to 415 grs, the new chrono speed is 285 fps, which still gives me the same K.E. and momentum, I was thinking with the draw length and arrow weight change my speed should have come up to around 300 fps, anyone have any thoughts?

Sounds a tad slow...have you had bow tuned lately...how did you measure 69.5 Lbs bow weight...calculate or actual weighed....?

Most with IBO of that bow is drop approx 10 Lbs down for every inch lower than 30"... couple FPS for 69.5 ..weight of arrow no more than 10 FPS so you should still be above 300 FPS

Neil

[brendan's dad]

Doesn't Mathews do something a little different when calculating IBO that may result in a less than accurate comparison to the normal industry standards? Maybe just a rumor and I never took the time to verify my Z7, but I recall something I read on archery talk with Mathews using an 80lb bow for testing.... Maybe just a rumor.

[L.O.S.T.Arrow]

Originally Posted by brendan's dad

Doesn't Mathews do something a little different when calculating IBO that may result in a less than accurate comparison to the normal industry standards? Maybe just a rumor and I never took the time to verify my Z7, but I recall something I read on archery talk with Mathews using an 80lb bow for testing.... Maybe just a rumor.

All bow manufacturers were obligated under IBO ratings if using IBO standards which are as follows...

And for the OP ..your MR 7 according to Mathews was 344 IBO

*How fast is your bow…Take rated IBO…
IBO speeds are based on a bow with a 30" draw set at 70lbs shooting a 350gr arrow.

-For every inch of draw length you go down you will lose 10 FPS
-For every 5# draw weight you go down you will lose 10 FPS
-For every 3 grains of weight your arrow is over IBO ( 5 grains per pound) you will lose 1 FPS
-For every 3 grains of weight you add to your string you will lose 1 FPS
so you can calculate approx speeds...

Having said that many bow manufacturers will push the 70 lb rule...use arrow with no vanes...on string with only wrapped nock point nothing else ...use mecanical shooter...all which exagerate speeds


Steps are in place such as with the ATA rating instead of IBO for realistic ratings....


Neil

[brendan's dad]

Hoyt Archery: Maker of the World's Best Bows For those with questions regarding ATA/IBO velocity: ATA speeds are 70 lbs, 30 in. draw at 5 grains per lb. IBO speed is commonly believed to also be tested at 70/30. However, in actuality, the IBO standards allow for speeds to be tested at poundages as high as 82 lbs as long as the arrow is at 5 grains per lb. By going with ATA spec, we eliminate any question as to how we test our speed. REAL SPEED. REAL NUMBERS.

Taken from Archery Talk. Sounds like IBO can be manipulated where as ATA has defined guidelines that put all bow on a level playing field.

[toddjler]

Originally Posted by L.O.S.T.Arrow

All bow manufacturers were obligated under IBO ratings if using IBO standards which are as follows...

And for the OP ..your MR 7 according to Mathews was 344 IBO

*How fast is your bow…Take rated IBO…
IBO speeds are based on a bow with a 30" draw set at 70lbs shooting a 350gr arrow.

-For every inch of draw length you go down you will lose 10 FPS
-For every 5# draw weight you go down you will lose 10 FPS
-For every 3 grains of weight your arrow is over IBO ( 5 grains per pound) you will lose 1 FPS
-For every 3 grains of weight you add to your string you will lose 1 FPS
so you can calculate approx speeds...

Having said that many bow manufacturers will push the 70 lb rule...use arrow with no vanes...on string with only wrapped nock point nothing else ...use mecanical shooter...all which exagerate speeds


Steps are in place such as with the ATA rating instead of IBO for realistic ratings....


Neil

Hey Neil I haven`t had my bow tuned yet, I had a shop in Edmonton use a spring scale to get the draw weight, I have peep and a d-loop on my factory string, I used the online archery calculator with an estimated 15 grs of weight on my string and it said I should be around 306 fps . I`m thinking im going to have to plan a trip and come get you to tune my bow for me

[L.O.S.T.Arrow]

Originally Posted by Ferrante

Are you stalling? If so, point the nose of your plane into the arrow and then speed up.

???