speed again...i know..

mauser06 · 01-30-2007, 10:24 AM

just curious about some things. i know i know it dont matter...and i truely dont care...was just kinda curous.

how much does increasing poundaged add to speed?? say going up in weight 3lbs.

how much speed will be lost from gaining roughly 100grs of arrow..how about 50??

is it true that aftermarket/gibblet strings will usually add a few FPS over factory strings??

just curious...im running numbers trying to find the best arrow wieght for my bow next year and have a good amount of KE. i know the mix is good speed and arrow weight. im running numbers to figure out where i want my finished arrow weight to land. im drawing 67lbs right now and im going to take it to 70..67 never bothered me..70 wont. i know i know i dont gotta pull 70lbs...but why not when i can? ive sat in my tree and shivered and never had trouble drawing 67 straight back..so im just kinda curious how much speed i'll be loosing and gaining by changing my setup..so i can pick an arrow weight to start shopping around for. too heavy and you loose speed..to light and youll loose KE..so im looking for my estimated speed after the modifications...thanx guys...

ps..i know i think to deeply into stuff. ive always been a math/numbers guy..like to play with them and see what happens etc..i know in reality it doesnt matter much..but finding the optimum setup and combination is my goal.

archer58 · 01-30-2007, 04:03 PM

For every pound of draw wt. u will pick up approx.2fps.
For every 5 grains of arrow wieght u will gain/loose approx. 1fps.

This is approximate and your bow's speed may change it a little.

mauser06 · 01-30-2007, 04:40 PM

awesome. looks like a 500gr arrow will be about optimum for me. giving me the best speed and best KE. looks like ill be at 240-250fps at 63-69 ft/lbs of KE. not a HUGE increase over my setup now...roughly 10-15 ft/lbs...but not a whole lot slower. the heavier arrow should penetrate better and shoot quieter..might even need to increase my DL..i know that gains FPS as well. thats something i want to get checked while im at the shop..from what everyone else says i may gain a half inch or a whole inch of DL. just looking to make my rig more hunting efficient more than anything else. thanx for the help..i know the numbers may differ from real life but ball park is close enough..and i know numbers mean nothing to a deer...

Phil from Maine · 01-31-2007, 03:26 AM

I know speaking about myself and my own expirence that with the heavey weights that control of my arrows is much better then the light wieghts I used to shoot. When target practicing on a calm day you can hear the broadheads cutting thru the air. For as far as distance you will loose some of it, but the hitting power is so much greater than you would realize. Just a few pounds on a broadhead can make a real noticable difference, it is hard to believe. For as far as distance I hit right on the mark at 35 yards, but, that pretty much maxes me out. Some folks here would laugh when they see those heavey wieghts fly out of my bow, but when they see the results the laughing stops. So Good Luck on what you decide.

mauser06 · 01-31-2007, 06:14 AM

thanx phil. after running numbers i found that a 500gr arrow in my set up will give me the best combo of speen and KE. a 550gr arrow i only gain a fraction of a foot pound but loose 10fps or so. thats..whats that called? theres a name for it but i cant recall right now. im not really looking for blazing fast arrows or flat shooting. i might practice out there a ways...but when it comes to shooting live game i wont shoot that far. i can smash arrows together at 35yds right now...but the only way id take that shot would be if i had a range finder and perfect conditions. no reason for me to stick with light arrows..exspecially being my bow isnt a fast shooter to start with.

YooperMike · 02-01-2007, 07:19 AM

I was shooting my 572 gr. arrows at 268. When I went with MAximas at 490 grains, they were going 289. Major increase in speed, and nearly identical enery. I am sticking with the heavy ones, but that is what I got when I went down about 90 grains.

KodiakArcher · 02-01-2007, 05:50 PM

Quote:

ORIGINAL: mauser06

thanx phil. after running numbers i found that a 500gr arrow in my set up will give me the best combo of speen and KE. a 550gr arrow i only gain a fraction of a foot pound but loose 10fps or so. thats..whats that called? theres a name for it but i cant recall right now.

Law of diminishing returns?

Straightarrow · 02-02-2007, 04:27 AM

Quote:

awesome. looks like a 500gr arrow will be about optimum for me. giving me the best speed and best KE.

It may be best on paper, but you have to be careful with making decisions that way. For instance, with your setup, a particular 550 gr arrow with an FOC of 15% may fly perfectly. Lowering the tip weight 50 grs, may leave you with a too-stiff arrow with a less than optimum FOC. Total arrow weight and speed is only a small part of what creates an effective arrow. You can have poor performing heavy arrows and poor performing light arrows. Where that weight is, in relation to the dynamic spine is the key to a great hunting arrow.

It's important for penetration, to put the weight in the right place. A 600 grain arrow with an FOC of 10%, may not penetrate as well as a 500 gr arrow with an FOC of 15%. The more involved I get into arrow tuning, the more I realize that it seldom works best to configure an arrow on paper without paying great attention to dynamic spine and FOC vs. draw weight and draw length. For me, this requires a lot of small adjustments with arrow length and draw weight for a given arrow combination.

The key to an effective hunting arrow is a lot of weight up front and a lot of drag in the rear, on a spine tuned arrow.

gibblet · 02-02-2007, 05:32 AM

on my end, some folks pick up speed, and i'd imagine some lose speed. it has to do w/ the material used, and w/in the same material it depends on strand count/ or weight. for instance, i can speed up a bowtech usually because they use more strands than i do on the shoot string, but i may slow down a mathews because they use less than i do. the twist count/inch will affect speed also - more twists means a slightly slower string (because more material is used so it weighs more)- but it can add in peep stability. its all trade-offs - and i think i make the best of them - but the folks who do it a bit differently than i do think the same thing
(even though they are obviously wrong LOL).