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I just had to break out my rusty algebra skills. With 44 cal lead (if all is correct) I would need at least 235 fps to be at or nearly 15 ft/lbs. I had to look up the equation. Energy = Weight (in grains) times Velocity Squared divided by 450395 (fixed constant) Then i had to find 44 cal weight in grains. 44 cal = .429 inch ? Used the ammo chart in downloads. approx 122 grains not quit 11 mm? Any suggestions or corrections? Balls are from a do-it slingshot pellet mold. Edit: mold info says 1/4 oz and that is only equal to 109 grains. Back to my rusty algebra.
 

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I need 248 fps with the 44cal do-it mold lead balls to reach 15 ft/lbs. Right?
The only way you can be certain of ball weight is to weigh them. Your alloy can vary weight by quite a bit. I have two Do-It molds and my current batch of .44 balls (actual diameter .429) cast mostly from wheel weights weigh 116 grains. To make it easy, here is an an Excel spreadsheet that will do the math for you. It gave me 242 fps with my balls for 15.09 lb/ft.

attachicon.gif
AmmoCalc.xls
Do I need a special scale?
 

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I used my homemade Beankung tube shooter.

Simple Shot Medium tubes with a Performance catapults pouch.

Overall length 12 1/4 inches, pseudo tapered approx. 6 3/4" loop, 5 1/2" single

1/2" steel from Simple Shot

Butterfly draw approx. 53"
 

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Hey Bean! That was some mean shooting! I had to laugh watching your eyes as you were stretching to do that full draw!!!! By the way, do your knuckles drag the ground when you walk??? :rofl: Yeah .... if we all had longer arms, we would all shoot a lot faster ...

Cheers ....... Charles
Lol .Glad you enjoyed it Charles. My knuckles are ok but, I am feeling it in the middle of my back. :)

Nice one bean! Thump!
Thanks Ben
 

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Great job Bean I knew a video was in the making. I was looking forward to it. Great job with those black latex bands I was wondering how latex would do for some serious power. :thumbsup:

Cheers

BC-Slinger
Thanks BC. Big ammo is fun, and scary. I think some Tex latex will rule the day. Loved your video.
 
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