calulating energy ft/lbs ?????

223

Distinguished Member
Hi

can anybody tell me or calculate for me the ft/lbs energy that the 2 loads below will produce ??????


load 1= 243(federal brass), 31 grains of n150, OAL 2.670 , sierra 100 spitzer bt(1560) , mean speed 2534 fps

load 2= 308(sako brass), 42 grains of n150, OAL 2.756, sierra 150 grain spitzer bt (2125) , mean speed 2405 fps

Many thanks

ATB
Dave
 
The way I always use...

Velocity x velocity x bullet weight divided by the magic number 450240 gives muzzle energy in ft/lbs

Not quite sure where the magic number comes from but I know part of it is that there are 7000 grains in a pound
 
The figure I use is: Divide by 450400 from my Lyman Manual. So, as given in a previous post, Bullet weight x Velocity x velocity, divide by 450400 = ft/lbs energy. Obviously downrange vel. & energy are important too.
Your .243 = 1425.65 ft/lbs & .308 = 1926.29 ft/lbs​
 
I think recoil is quite a subjective thing and also dependsa lot on stock design. I have not fired a .600 nitro, but have shot .577 nitroand .50 BMG neither of which were particularly unpleasant to fire. Conversely, ashooting companion had a .300 WM which was very anti social until he changedthe stock from wood to synthetic. A chap I know also had a deer legal .44 whichwas no fun to zero. Both of these calibres produce a fraction of the recoil ofthe big bores, but for some reason I didn’t get on with them.
Mike
 
One of the reasons I was asking is that when I took the dsc1 I used the basc rifle, a 6.5 x 55 Tikka T3. This was nice to shoot and easy to keep the sight picture when taking the shot.

For many reasons I later got a .308 which I really like but the recoil is such that I can't keep the sight picture. Long story long..I'm thinking of getting a .308 load which equates to a 6.5 in recoil.

Sorry .223, I'm hijacking the thread a bit but hopefully it's of interest.

fraser
 
...For many reasons I later got a .308 which I really like but the recoil is such that I can't keep the sight picture. Long story long..I'm thinking of getting a .308 load which equates to a 6.5 in recoil.....

private fraser - a good sound moderator and bipod will add to the overall weight and should make it easier to shoot. Good luck. JCS
 
Back
Top