# speed and projectile weight for f.p.e



## Nicholson (Sep 25, 2012)

So now that I have a chronograph I think its time to start earning some badges. I think the first one I'll go for is the power ranger badge. So, I hate math. How do I take the speed and weight of the projectile to equal the foot pounds of energy? next question is, I dont have a scale is there a listing of projectile weight for steel and lead balls, or do I have to go out and get a scale now too :/


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## M.J (Nov 1, 2010)

Here you go, there's an Excel file in the post that you plug your ammo and speed in to and it spits out fpe numbers:
http://slingshotforum.com/topic/3586-ammo-calculator/


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## Charles (Aug 26, 2010)

Buy a simple digital scale:

http://www.leevalley.com/en/garden/page.aspx?p=68352&cat=2,40725

This one is cheap, but works very well. You can weigh ammo of any size or material ... steel and lead balls, hex nuts, stones, candy, glass, ... You can change to whatever units you want ... grams, grains, ounces ...

It costs less than $20 ... skip one night at the pub and buy a scale.

Cheers ... Charles


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## wll (Oct 4, 2014)

Charles said:


> Buy a simple digital scale:
> 
> http://www.leevalley.com/en/garden/page.aspx?p=68352&cat=2,40725
> 
> ...


What, What was that you said Charles ...Skip one night at the pub ! .... blaspheme ;- )

wll


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## Charles (Aug 26, 2010)

wll said:


> Charles said:
> 
> 
> > Buy a simple digital scale:
> ...


I take your point ... O.K., so skip a couple of days at Starbucks ....

Cheers ... Charles


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## wll (Oct 4, 2014)

Charles said:


> wll said:
> 
> 
> > Charles said:
> ...


Yes, I agree, cheers !

wll


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## Rocketeer67 (Oct 6, 2014)

These might help http://www.1728.org/energy.htm

http://melchiormenzel.de/info_ammo.html

Hope this helps let me know how you go on

Kindest regards Kenny


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## Nicholson (Sep 25, 2012)

Rocketeer67, I put some numbers on the slingshot bands and tubes section of this forum. but I'm waiting to receive a scale I ordered to make my numbers official


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