# Foot-pound recommendations seem high?



## Clever Moniker (May 12, 2013)

So I downloaded this energy chart which is freakin' awesome btw:

http://slingshotforum.com/files/file/91-slingshot-hunting-energy/

So I don't know if this goes in the noob section or the hunting section. lol BUT, if you only need 5 foot-pounds to kill a rabbit... why are the recommendations so high?


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## dannytsg (Jun 16, 2013)

The main thing with hunting is to ensure that if you don't kill you can still debilitate, retrieve your quarry and finish it off.

A 5ft/lb shot to a bunnies body will not do that an you are more likely to harm and animal and not retrieve it. It's always better to have more power for those instances when you don't kill outright.

It's also safe to say that with single or double TGB you are generally going to be producing more than 5ft/lbs time after time. Don't ge too hung up on having too much power but ensure you don't have too little.

Practice practice practice is always the key.

Dan


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## Charles (Aug 26, 2010)

Just a couple of examples:

120 grain ammo (about .44 caliber lead) at 175 fps yields about 8 foot pounds of energy.

140 grain ammo (my cylindrical lead hunting slugs) at 175 fps yields about 9.5 foot pounds of energy.

Personally, I like ammo in this range for hunting. And it is pretty easy to get it up to 175 fps with bands that will not rip your arm muscles loose when you draw them.

Of course, all other things being equal, more energy is better. You do not want the ammo to be too light to be effective. But the most important factor is accuracy. If the bands are too heavy, you will not be able to shoot accurately. Shooting 15 foot pounds of energy is probably over kill for small game. Personally, I think 5 foot pounds of energy is under powered unless you are very, very accurate.

Cheers ..... Charles


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## wll (Oct 4, 2014)

Very old 2 year old thread, but still a viable thread, ---- I'm assuming you are talking about 5fbs at Point of Impact (POI) is enough for small game ....Pigeons, squirrel, rabbits, crow and the like. If not what, energy at POI do you think is enough ?

wll


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## Charles (Aug 26, 2010)

Using a ballistics calculator for round ball:

http://www.ctmuzzleloaders.com/ctml_experiments/rbballistics/rbballistics.html

we find that a .45 lead ball with an initial velocity of 175 fps, will be going 165 fps at 10 yards and 156 fps at 20 yards. Using this calculator for foot pounds of energy:

http://www.pyramydair.com/article/What_is_Muzzle_Energy_August_2003/5

we get 8.27 foot pounds at 10 yards, and 7.39 foot pounds at 20 yards.

Personally, I would not use a slingshot for game at 20 yards ... but to each their own. For me, accuracy is the problem.

As for the lower limit of acceptable energy ... well, I do not really have a precise figure. But just given my own experience and gut feeling, I would hesitate to drop down to 5 for a weapon that depends on blunt force trauma.

Cheers .... Charles

P.S. For a .45 lead ball, at about 137 grains, your velocity has to drop to between 125 and 130 feet per second for the energy to drop down to 5 foot pounds. When you think about it in those terms, I think you can see why I think 5 foot pounds of energy is just not enough.


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## wll (Oct 4, 2014)

Charles said:


> Using a ballistics calculator for round ball:
> 
> http://www.ctmuzzleloaders.com/ctml_experiments/rbballistics/rbballistics.html
> 
> ...


Charles, I'm in 100% agreement with you.

Anyone who reads these forums knows that I like heavy ammo at a good rate of speed, although also saying that my general slings need to put out too.

After going through all the figures and my testing, with a reasonable tube set at my draw I can shoot 1/2" steel at about 215fps, sometimes faster, but as an average. If I go throw the numbers I'm getting 10fpe at 25 yds (a "normal" long range shot) and this fpe is OK for all accounts for hunting small game with a sling.

If we extend this range another 25 yds, we end up with 7fpe. Not the greatest, but still in the ball park for small game.

I'm not saying folks should hunt with a sling at 50yds, but I'm saying it still has a potential of long range power.

It is this reason that for me ammo in the 130-150gr range and around 200+fps is the lowest I would ever go for for sling shot game

Yes, I do shoot marbles and 7/16" steel, but for me that is for pest birds. There are lots of folks that use marbles for larger game, but they are able to get within a 10-15 yrd area .... it will be a cold day before that happens where I live, even if it was legal.

wll


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