http://extorian.co.uk/shooting/pellets.html
depends on pellet weight
8.4 grain@ 780 fps= 11.35lbft
8.4 grain @ 1000 fps=18.66lbft
hi there
im looking for information
how to convert
780fps to ft lbs
or a 1000fps
ive found nothing to help
so im wondering if anyone here can
thanks
http://extorian.co.uk/shooting/pellets.html
depends on pellet weight
8.4 grain@ 780 fps= 11.35lbft
8.4 grain @ 1000 fps=18.66lbft
aa s409k .177, cs700 stock, mtc mamba 4-16x50, logun qgs
thought they had 3 power ratings that you could switch between,
aa s409k .177, cs700 stock, mtc mamba 4-16x50, logun qgs
but to err is human my friend
Rapid 7 / 10-22 ATN 2 Stiller Predator .204 Pulsar N970 Tikka T3 semi custom ATN MARS thermal.204 Tikka T3 Semi.223 Wylde IOR Operator Lawton 6mmBR Kahles Gen 3 - Stiller 6.5 x 47 Bushnell BDX - Winchester Red Performance SX3 12g
You need to know the weight of the pellet in grains (some tins do have the weight written on them).
Say you are using a pellet that weighs 7.5gns.
The formula is:
Muzzle velocity squared, multiplied by the weight of the pellet, divided by 450240.
The result is in ft/lbs.
780x780=608400
608400x7.5=4563000
4563000/450240= 10.13ft/lbs.
This is a formula that I have used since the 70's so there may be an easier or better method of working it out and if this is the case I'm sure that someone will come along and correct me.
I hope this is of assistance.
Regards,
Gary.
Try this:-
http://www.1728.com/energy.htm
Theoben MFR CS800 .177/Burris Timberline, Theoben Evo .177/ Burris Timberline, BSA Supersport .25, Haenel XX, BSA Ultra .177/ Burris Timberline.
>>Muzzle velocity squared, multiplied by the weight of the pellet, divided by 450240
Spot on. Looks a bit weird but it's because of the units used - grains, pounds, and feet.
The kinetic energy of a pellet leaving the barrel is:
(pellet weight x (speed x speed)) / 2
This is nice and easy using SI units:
(Kg x (m/s x m/s)) / 2
i.e. (pellet weight in grams / 1000 x (speed in metres/second x speed in metres/second)) / 2
The result is the energy in joules.
It gets a bit messy in imperial because grains isn't a simple fraction of a pound. But the figure of 450240 is a simple way to convert grains to pounds and also apply the division by 2 in the formula. So, you put in feet/second and grains and out pops the energy in lb/ft.
go here dude
http://www.theoben.co.uk/pages.php?pageid=5
some good sites here people
thanks alot
I think what the man is after is, the theoretical maximum muzzle velocity of a 12 ft/lbs air rifle, depending upon the weight of the pellet being used. At the end of This Link, is an image of the usual formula re-arranged to make Muzzle Velocity (in feet per second) the subject. You'll need a calculator with a square root key - use Windows' own calculator. Regards ... Geek
PauL H. - Shotgoon
Brownings: 1999 Ultra XS; 2004 B525 Field; 2010 Maxus Hunter: Air Arms 1998 Mk.2 Pro-Target, 2001 Mk.2 Pro-Sport & 2003 S400C
ok thanks
but how do i find the Muzzle velocity
on a air rifle ?
thanks
Click
You can edit the pellet list to add your pellet and weight, (look in the help file) then you can input the required ftlb and it will tell you the fps for the selected pellet, or you can input the fps and it'll tell you the power.
Alan.
If you don't know the muzzle velocity you can't work out the kinetic energy in ft/lbs.
I don't understand why you give a fps reading for conversion, then you ask how to find out how to get fps.
You can buy inexpensive chrono's (Combro) for about £40 that attach to the end of your muzzle and they will give you a read out in fps. They can also convert this into ft/lbs if you know the weight of your pellet.
Regards,
Gary.