[Archie]

It is complicated. The simplist answer is that all bullets are internally different (duh!) and therefore have differing resistance to entering the rifling.

Contrary to popular or intuitive thought, lead bullets run higher pressures than jacketed. Either because they seal off the bore better, or they drag on the bore more, being softer. Maybe both.

A hollow point might "give" a little more than a FMJ. Or it might have a "harder" alloy.

Bottom line. Start low and work up. If recoil gets more than what you think it ought to be (compare to factory), or noise levels are harsher, you might back off just a might. Certainly for general practise, plinking or target work a "max load" is unneeded.

Defense loads shouldn't be maximal for that matter. You want control and reliability. Having your pistol come undone in the face of the unholy is not a desired result. To some extent, hunting loads have to be reliable and function under all climates.

End of sermon.