1. these are power factor (PF) for given lengths of barrel.
2. PF is a measure of momentum.
3. momentum is a direct result of gunpowder. KE is a secondary consideration.
4. experimentation with a wide range of ammo in each length of barrel gave the following data and revealed that KE and velocity varies with bullet weight but PF does not. i.e. momentum is conserved between gunpowder and bullet.
5. a PF of 5 makes little difference in terminal effect although it can be slightly
felt in recoil. a PF of 10 does make some difference in terminal effect.
6. quite often an ammo can be:
A. more powerful in a short barrel and lose power with a longer barrel, due to fast burning powder.
B. more powerful in a long barrel yet come up a little short in a short barrel, due to slow burning powder.
7. it has been determined that the bullet would gain PF linearly from 3.5" to 5.3", in an ideal model, but never does "exactly" because of the properties of faster or slower burning power. most of the ammo you use will be slightly better suited to a longer or shorter barrel.
8. G24 (6" bbl) has been left off due to nonlinearity. the cartridge runs out of gas quite rapidly after 5.3", maintaining mostly the same velocity with little acceleration. G35 (5.31" bbl) is optimal.