Kinetic energy

[Bow Walker]

Sounds good.........let me know.

[J_T]

Hey guys, isn't there some guidance provided somewhere or a rule of thumb or perhaps its a law somewhere that says an arrow must (I can't remember) either have a minimum weight, or must be 10 grains for each pound of bow pull.

IE I shoot a 64 pound bow therfore a well matched/efficient arrow for my bow is a 640 gr arrrow.

I might be way out in left field here. I haven't thought about this for some time.

JT

[Tuffcity]

J T,

I think that the 10 gr/pound is more of a guide line for trad setups. IIRC it roughly averages out bow efficiency with an adequatly massed arrow to achieve decent speed, quietness and penetration potential.

Could anyone please tell me what the minimum should be to hunt with.

I think that minimum draw weight within an archers draw length is a better guideline for hunting. With minimum KE requirements you will exclude lower poundage stick bows that will cleanly kill game if decent weight arrows are used.

KE is a better indicator of bow efficiency than actual "killing" power. Calculate the force your arrow produces and see how it stacks up. Certainly not nearly the manly numbers that KE calculates out at but probably a better indicator of the potential to push an arrow through something.

RC

[J_T]

Thanks RC.

[pupper]

Thanks for the post and the formula Pupper. I went looking for it in my stuff and couldn't find it.

I shoot a 64# recurve, 200 fps and a 750 gr wood arrrow. Works out to 67 ft lbs of energy.

I just made up some carbon arrows, thinking lighter (flatter trajectory) and I was able to build an arrow weighing 630 gr. This new arrow now gives me 56 ft lbs of energy.

If you want more KE >> go heavy.

JT

I dont know if going heavy is the answer because velocity is squared in the calculation so every fps faster you actually gain twice as much in the calculation. plus going heavier takes away from shooting flatter.

Justin

[pupper]

(315x315)x415/450250=91.45669.Hoyt Cybertec 80lb 31"draw 27"415grn arrow.

is that chrono speed or advertised speed?

with a drawlength at 31" i guess that number is very attainable!!!

[Tinney]

KE is relative. Gah this is the same as energy from a rifle....he with the most has the biggest...err....ego

Shot placement will forever rule supreme.

[pupper]

KE is relative. Gah this is the same as energy from a rifle....he with the most has the biggest...err....ego

Shot placement will forever rule supreme.

what if shoot a thick hided animal in the right spot but it cant penetrate?

then is shot placement still supreme?

[Tinney]

What animal are you hunting in BC that has a thick enough hide that ANY modern bow cannot penetrate!?

[J_T]

what if shoot a thick hided animal in the right spot but it cant penetrate?

then is shot placement still supreme?

Nope, if you can't penetrate it's a question of the leading edge of your arrow. The broadhead.