Thread: Energy/pressure relationship

I was looking at my figures and it got me thinking.
Can energy at muzzle be an indicator of similar pressures?
ie if you had a 140gr pill giving 2500 ftlbs at the muzzle would it be similar pressure to get a 162 delivering 2500 ftlbs at the muzzle (dont get me wrong I use standard pressure signs for assessing my loads this is more just wanting to understand something from a theory perspective)
You would think it would take the same energy input to cause the same potential energy output wouldnt you? (assuming similar bearing surface)