Broad head wt. in relation to spine

[Lafitte23]

I'm currently shooting beman 350's with a 100 grain head. I was told that 350's may be a little stiff for my set up. Would changing to a 125 grain have any effect in relation to spine (ie make it act stronger or weaker)? Also I've noticed that the weaker spined arrows are lighter (gr/inch) than the stiffer ones. How would I go about moving to a 400 spine and still keep my total arrow weight up?

CP

[atexx2]

changing to a 125gr will not change the spine, but it will change the FOC. Don't know about the other question.

Changing the weight will have an effect on the over spined/underspined arrows.

I would be experimenting with paper tuning, then walkback tune, to get the best flight

[Lafitte23]

atex

Is there any such thing as too much FOC?

[atexx2]

yes, i was noticing that my groups were larger at 30 yds and more so i was reading some stuff and read about FOC so i figured mine out and changed to 125gr and groupings tightened up. It worked for me

[old killer]

Three things that effect spine are, Point weight, arrow length, and draw weight. Though the spine is fixed once cut, the other two items will change the flex of the arrow. The easy way to see the point weight change the spine is to shoot a 75gr point through the paper and repeat with a 125 or 150gr point.

[bowhuntntxn]

I strongly disagree with the 125 not affecting spine. adding weight to the front of an arrow weakens the spine, and adding weight to the rear of the arrow makes the spine stiffer. BHs have a tendency to shoot a little better when on a stiff spine rather than a weak spine.

[Mudslinger]

Changing the point weight or the weight at the fletch end of the arrow will definitley affect spine. Going from a 100 to 125 grain point will not affect spine much, but it will impact the FOC some. I have always liked a stiffer spined arrow for my set up, to me it is a little more forgiving if it is not to stiff. i was a proponent of the lighter faster arrow up until recently when I did some testing and i am fixing to go from a 410 grain arrow to somewhere in the neighbor hood of a 510 to 560 grain arrow. More FOC, KE and Momentum, plus a lot quieter on the shot. if it was me i would stick with what you have especially if it flys well with FP's and BH's.

[atexx2]

I knew i would get corrected on that , thanks for correcting me, here is some more helpful stuff that i found.

USEFUL FACTS ON ARROWS

Spine = reference to the stiffness of an arrow. Lower draw weight bows require an arrow (normally less in weight) with a weaker spine while a bow with higher a draw weight require an arrow (normally heavier in weight) with a stiffer spine. During the shot the arrow has to handle and correct itself in flight from the shock of the bows shot. The proper arrow will deliver more consistant results.

Spines can be altered by increasing the arrows length (to make it an arrow of a weaker spine) or by decreasing the arrows length (to make it an arrow of a stiffer spine). Tip weight also can alter the spine. By increasing the tip weight the spine weakens and by decreasing the tip weight, the spine stiffens. These techniques can be used when fine tuning an arrow to reach proper spine for the given compound bow.

Grains = the unit of measurement when weighing arrows and its components. Good electronic grain scales can be purchased off Ebay for under 10 dollars and is a nice item to have for the serious archer.

Most manufacturers require you to shoot an arrow with a weight equal to 5 grains or more per pound of draw. If you are shooting a 70 pound bow, then in order for the bow to be covered under most warantys, you must shoot an arrow (including tip) that weighs at least 350 grains. Too light of an arrow will not absorb enough of the energy of the bow and may result in the bow eventually failing due to the lack of an energy transfer.

Most current bows which are tuned can shoot an arrow as close as possible to the 5 grains per pound of draw rule and still have plenty of kinetic energy to kill a whitetail deer. When hunting bigger game, heavier arrows are preffered by some but speed is then sacrificed.

When choosing the length of the arrow, consider that the arrow should be at least a 1/2 inch forward of the arrow rest.

**SUMMARY

Arrows are not cheap; if you want to buy an arrow with the proper spine and as close as possible to the 5 grains per pound requirement for maximum speed, access an archery program or someone who owns a program. Most quality proshops will have one. Buy a 1/2 dozen to save on costs and shoot at different bulleyes on targets when practicing to ensure you do not damage your arrows. Robin Hoods (result of an arrow being shot into another arrow) are a nice conversation piece, but they can get expensive.

[Lafitte23]

Thanks for all the info guys! Mudslinger I'm also wanting to shoot heavier arrows (at least for hogs). What brand/type of arrow would you suggest to get that 400+ grain set up? The ones I have looked at in the 350 to 400 spine come no where close to reaching 400 grain total at 26.5 inches. Also how much would be too much FOC?

[ken]

A Gold Tip 5575(400 spine) with a 125 grain point would put you around 400 grains. You didn't say what your draw weight is so you will have to check the manufacturer's charts to see what spine arrow you should be shooting.

[Lafitte23]

Thanks Ken. I'll check that out. I'll probably be shooting 60-65 lbs. with 27.5 inch draw length.

[Texastaxi]

To get your weight up, you can always shoot a longer, stiffer arrow ... they don't HAVE to be cut to match your draw length.

I also put weight tubes in my FMJs to get the total weight up to about 630 grains.
Speed is nice, but after you shoot a heavy arrow, feel, and HEAR the difference, speed becomes an afterthought.

Oh, the heavy arrows hit like a sledge hammer too!

[Lafitte23]

Are these heavier arrows always aluminum? Do they make carbon arrows that heavy?

Taxi I'm definitely looking for something that hits harder. I made a bad shot on the last hog I killed and hit him directly in the shield. I got very little penetration but luckily hit an artery.

oh and quieter bow would be a big bonus!

[WGMitch]

Awesome...

This is great stuff. I have read this before, but it is always good to revisit information such as this to refresh the brain.

I knew i would get corrected on that , thanks for correcting me, here is some more helpful stuff that i found.

USEFUL FACTS ON ARROWS

Spine = reference to the stiffness of an arrow. Lower draw weight bows require an arrow (normally less in weight) with a weaker spine while a bow with higher a draw weight require an arrow (normally heavier in weight) with a stiffer spine. During the shot the arrow has to handle and correct itself in flight from the shock of the bows shot. The proper arrow will deliver more consistant results.

Spines can be altered by increasing the arrows length (to make it an arrow of a weaker spine) or by decreasing the arrows length (to make it an arrow of a stiffer spine). Tip weight also can alter the spine. By increasing the tip weight the spine weakens and by decreasing the tip weight, the spine stiffens. These techniques can be used when fine tuning an arrow to reach proper spine for the given compound bow.

Grains = the unit of measurement when weighing arrows and its components. Good electronic grain scales can be purchased off Ebay for under 10 dollars and is a nice item to have for the serious archer.

Most manufacturers require you to shoot an arrow with a weight equal to 5 grains or more per pound of draw. If you are shooting a 70 pound bow, then in order for the bow to be covered under most warantys, you must shoot an arrow (including tip) that weighs at least 350 grains. Too light of an arrow will not absorb enough of the energy of the bow and may result in the bow eventually failing due to the lack of an energy transfer.

Most current bows which are tuned can shoot an arrow as close as possible to the 5 grains per pound of draw rule and still have plenty of kinetic energy to kill a whitetail deer. When hunting bigger game, heavier arrows are preffered by some but speed is then sacrificed.

When choosing the length of the arrow, consider that the arrow should be at least a 1/2 inch forward of the arrow rest.

**SUMMARY

Arrows are not cheap; if you want to buy an arrow with the proper spine and as close as possible to the 5 grains per pound requirement for maximum speed, access an archery program or someone who owns a program. Most quality proshops will have one. Buy a 1/2 dozen to save on costs and shoot at different bulleyes on targets when practicing to ensure you do not damage your arrows. Robin Hoods (result of an arrow being shot into another arrow) are a nice conversation piece, but they can get expensive.