What arrow mass will achieve tha maximum momentum?

Black Stick · 05-14-2008, 11:05 PM

What arrow mass would achieve maximum momentum (Momentum=Mass"¢Velocity)? Someone mentioned that there is software that can give that figure in an earlier post. One of my buddies got a Grizzly tag and he asked me to go along. I probably wont need to take a shot, but if I have to, I will. With grizzly, I want to hit them as hard as I can.

I realize that this will be different for every set-up, but it's something that I'm sure a lot of people want to know. What is going to hit the hardest? Look at my signature for specifics and if you need anymore details, just ask. Thanks.

Black Stick · 05-14-2008, 11:09 PM

30 inch draw. I know I said I had a 31 inch draw in another post, but that was before I started shooting with a release. 73 lbs hurts like hell on the fingers after 100 shots in the range. I didn't even use a tab or glove. They just irritate me.

05-15-2008, 05:53 AM

Generally the heaviest arrow will give you the most momentium. I would try to find a balance of energy and momentum

Black Stick · 05-15-2008, 07:58 AM

Quote:

ORIGINAL: bigcountry

Generally the heaviest arrow will give you the most momentium. I would try to find a balance of energy and momentum

I was thinking that there would be a certain arrow weight that would have the highest momentum. If you started with the minimum arrow weight and moved towards the maximum, you would get a curve like this:

Black Stick · 05-15-2008, 08:02 AM

Lest say that arrow mass is on the x axis (across) and momentum is on the y axis (up & down), what is the arrow mass at the peak of the curve? How hard can I hit 'em?

OHbowhntr · 05-15-2008, 08:11 AM

Bryce,
You sound like you want some SPEED too, so I'm punching numbers and at 30" and 73#, assuming you have speed mods on that 82nd, and the birth certificate is close to 342 IBO, correct me if it's not (Bowtech's are notorious for being below the "advertised IBO"). But if your bow CAN spit out a 342 IBO, based off of that guestimate, you can get a 560gr arrow to zip real close to 300FPS, while packing a WHOPPING 111.92 ft/# of KE and .7457 slug/ft of momentum. That's almost enough energy to punch through and ELK shoulder, and certainly enough for ANY whitetail or bear, provided you have a sufficient BH on the fore-end of that arrow.
Really want speed, you can put a 450gr arrow out there at 322fps, while holding onto 103.98f t/# of KE and .6444 slug/ft of momentum.

Wanna save your shoulders, drop the draw-weight to 65#, and you still can launch a 450gr arrow at 308fps, with 94.9 ft/# of KE and .6156 slug/ft of momentum, still more than enough energy for anything here in North America, while giving yourself a little "safety valve" on one of those cold MN mornings when the muscles aren't sure if they're up to the challenge.

FWIW, an IBO arrow would give you 93.71 ft/# of KE, with .55 slug/ft of momentum. So a 560gr arrow would be very much quieter, though a bit slower, but would pack 35% more momentum, and 19% more KE. But you could feasibly drop weight to 65# w/ a 450gr. arrow as mentioned, and still gain about 12% momentum, while picking up or maintaining about the same KE as an IBO arrow at 73#.

For $25 you can get a copy of OnTarget2 here: http://www.pinwheelsoftware.com/ or you can get the FREE TRIAL version to see if you like it, then buy later. It's a nice program to have, and guides you through a variety of set-ups so you can decide what "should" work best for you, whether it is CHASING FPS, or launching a fence post.

Hope some of that helps!!!

bow_hunter44 · 05-15-2008, 08:12 AM

While the curve you reference will be different for every bow, in theory I would have to agree. I would LOVE to see the scale on the x and y axis!!

Black Stick · 05-15-2008, 08:12 AM

Also, it would save me a lot of work calculating which shaft, fletch, nock, and head combo would get me close that weight. The shaft has got to be black carbon and the head has got to be a Magnus Snuffer screw-in. They come in a lot of sizes, The fletchings have got to be either 4" of 5" feathers, and the nock has got to light up. Sorry for being so picky.

Black Stick · 05-15-2008, 08:19 AM

Quote:

ORIGINAL: OHbowhntr

Bryce,
You sound like you want some SPEED too, so I'm punching numbers and at 30" and 73#, assuming you have speed mods on that 82nd, and the birth certificate is close to 342 IBO, correct me if it's not (Bowtech's are notorious for being below the "advertised IBO"). But if your bow CAN spit out a 342 IBO, based off of that guestimate, you can get a 560gr arrow to zip real close to 300FPS, while packing a WHOPPING 111.92 ft/# of KE and .7457 slug/ft of momentum. That's almost enough energy to punch through and ELK shoulder, and certainly enough for ANY whitetail or bear, provided you have a sufficient BH on the fore-end of that arrow.
Really want speed, you can put a 450gr arrow out there at 322fps, while holding onto 103.98f t/# of KE and .6444 slug/ft of momentum.

Wanna save your shoulders, drop the draw-weight to 65#, and you still can launch a 450gr arrow at 308fps, with 94.9 ft/# of KE and .6156 slug/ft of momentum, still more than enough energy for anything here in North America, while giving yourself a little "safety valve" on one of those cold MN mornings when the muscles aren't sure if they're up to the challenge.

FWIW, an IBO arrow would give you 93.71 ft/# of KE, with .55 slug/ft of momentum. So a 560gr arrow would be very much quieter, though a bit slower, but would pack 35% more momentum, and 19% more KE. But you could feasibly drop weight to 65# w/ a 450gr. arrow as mentioned, and still gain about 12% momentum, while picking up or maintaining about the same KE as an IBO arrow at 73#.

For $25 you can get a copy of OnTarget2 here: http://www.pinwheelsoftware.com/ or you can get the FREE TRIAL version to see if you like it, then buy later. It's a nice program to have, and guides you through a variety of set-ups so you can decide what "should" work best for you, whether it is CHASING FPS, or launching a fence post.

Hope some of that helps!!!

That's perfect. I will consider dropping to 65#, but 73# if pretty easy to pull. I shoot it 100 times a day in the range. Probably because I'm a swimmer and my back is strong.

I will certainly get that program. Thanks for your help.

OHbowhntr · 05-15-2008, 08:20 AM

Quote:

ORIGINAL: Black Stick

Lest say that arrow mass is on the x axis (across) and momentum is on the y axis (up & down), what is the arrow mass at the peak of the curve? How hard can I hit 'em?

MAXIMUM KE, based on the rough numbers I'm using for your set-up would get you 114.51ft/# of KE w/ a 675gr arrow, the Momentum DOESN'T peak out on OT2, I get .93 slug/ft with a 999gr arrow, which is tops I can go to.