N/A Muzzle energy varies with pellet weight, WHY?

[Scotchmo]

That number can be found to be different in many places, sometimes rounding differences, one time long ago it changed with a more accurated definition of gravity. The number is basically 7000 grams squared * acceleration of gravity in ft/second squared. It doesn't matter, anything close doesn't change anything unless looking out to many decimal places.

What would the muzzle energy formula be if it were calculated in deep space, where there is no gravity?

Ok. I already know the answer. And the actual muzzle energy is the same on the earth as it is in space, and gravity has nothing to do with it. If you use weight and the estimated acceleration of gravity, you can introduce other errors. Use mass instead as that’s what the kinetic energy equation calls for. I convinced AAFTA to use 450,436 because that is the more correct (though rounded down) value.

 

[Mycapt65]

I can't add to the excellent notes above - and this is a detour from the OP's question - but I would note that heavier pellets tend to have better ballistic coefficients, and thus retain velocity better.

In other words, energy at the muzzle is not the whole story. The heavier pellet that starts with less energy, often delivers more downrange than the lighter one.

While theoretically that's true, a heavy pellet's BC seldom makes up for the lower muzzle energy in the distances springers are shot. My R1 was 17 fpe with a 8.64 FTT and 12.5 FPE with a 10.65 Barracuda. The distance required for the two to even hit the same energy I'm sure would be well past the practical range of the rifle. This is a drastic case example but typically BC improvements within a caliber are slight and don't make much difference at typical airgun ranges. Unless you compare extremes like Hobby wadcutters to JSB heavies. In that case you'd be right but you might still have to go 30 yards before the heavies pass the hobbies noticeably.

Energy, drift and velocity retention improvements from an improved BC typically need long distances to reveal themselves. Longer than most springers are shot.

be well Mike
Ron

 

[JEFFPPC]

Well Ron pick your poison. If want simplicity but with a learning sure you want s Springer. Out to 50 yds in good conditions by a competent shoot they will pretty much stay with a PCP. But if you want to shoot farther, shoot larger calibers, and as far as shooting technique not really much to learn you will enjoy a PCP. Now all the theory in the world will not have you shooting x's, that takes practice.Take those graphs or charts, put a dot in the middle, and start shooting at it. Have fun.