Range Report FGMM energy discrepancy??

[hydro556]

I dont shoot factory ammo much anymore, and I am trying to figure out the energy discrepancy between different lots of FGMM 168 grain match ammo.

I have about 15-20 boxes of the older FGMM in the blue and white boxes and about the same in the newer red and black boxes. Both are 168 grain SMK's.

On the back of the box, both claim a muzzle velocity of 2600 fps. Yet, the white box stuff claims a muzzle energy of 2520 ft. lbs and the black/red box claims 2625 ft. lbs.

I am no physicist, but I thought energy was a result of mass multiplied by velocity. How can 2 168 grain bullets traveling an identical 2600 fps yield different energy levels?

There must be something my feeble mind is missing. Can someone explain?

 

[hydro556]

Re: FGMM energy discrepancy??

nobody

 

[kraigWY]

Re: FGMM energy discrepancy??

Don't know unless one realy has 175s.

168s would be 2522
175s would be 2627

Assuming they both have the MV of 2600 FPS

 

[hydro556]

Re: FGMM energy discrepancy??

They both claim to be 168's but the numbers you mention are correct.

My rifle shoots the blue/white box stuff very well. Well enough that I hate not to shoot it, even though I reload.

I am selling half of it, and am selling the newer red/black boxed stuff. I was just wondering about it because I found it odd.