# How does the amount of grain affect the Bow or shot??



## mike 66 (Jan 21, 2010)

what i think would be most important for you is you dont want to light of a arrow or a under-spine shaft for your bow example; say you have a 70 lb bow .never shoot a wood arrow in it. or a light under spine arrow.. when you release it the force of the energy from the bow will snap the arrow and the shaft might stick in your arm and come out your finger.the term grain is a measurement term also used on arrows to determine the weight of a shaft... the more weight the more kinetic energy you get, it also helps the bow absorb the energy making the bow more quiet.. but you loose speed, but you gain ke....we use the grains per inch to calculate the weight to get what we want.say i need a 450 grain arrow, at 28 inches, the shaft needs cut to get there so take 9.0 grains per inch off and you have...whatever..+fetching+tip+ inserts+nock+ insert=450 grains.. read up on kinetic energy, foc.spine, archers paradox. this will help you a lot.welcome to AT new guy...mike


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## aread (Dec 25, 2009)

Good advice from Mike! Make sure you have an arrow with enough weight. Ignore those who emphasize speed and recommend light arrows. Arrow speed is good, but it is way down the list. Heavier arrows are quieter and will penetrate better.

There are 437.5 grains per ounce. For most purposes a few grains variation doesn't matter. But target archers try to build their arrows consistent to within 1/10 grain. Closer is better, but don't get too worked up over 10 or 15 grains variation.

If you want to really get into arrow design for hunting, read Dr Ashby's reports. You can find them on the Alaska Bowhunting Supply website and the Tradgang.com website. Dr Ashby spend many years studying how an arrow kills and how to make it more effective. His full set of reports is a great way to put yourself to sleep, but his final recommendations are mostly common sense, but with a few things that may surprise you. He is a strong proponent of heavy arrows.

It's difficult to build arrows that are too heavy, but it's pretty easy to build them that are light enough to damage your bow.

Hope this helps,
Allen


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