I could go into powder curves and an example in one I loaded for where it was short stroking and increasing the charge made ie worse . Which at first glance doesn't seem related but if you let the gears turn a while makes a good relationship.
You have a pressure limit with a desired pressure window at a particular point . In principle with a 50kpsi peak and 15 kpsi at the gas port both bullets should depart the muzzle with the same pressure . But some powders look like ^ and some are more like ✓\ while a 3rd is more like ✓~~\ .... One hits fast to peak and drops off just as quickly with just enough left to cycle , the second has a a nice fluid arc with a moderate rise to peak and the back side is coming down just in time to trip the action while the 3rd powder has a slow rise to peak , long hold and is still pushing with the bolt unlocking . A might only have 2000-2500 psi left at the muzzle with the lighter bullet something like 10x . H 322 or 335 might have 5k left with either bullet but 322 is likely to be lower with the heavier bullet . Meanwhile H4198 will be slow to peak with a very long hold and still have 10k at the muzzle with the heavy and 9-11 k with the light bullet . These 4 powders live in about 10 steps on the burn rate charts .
This assumes for example a 90/95 gr vs a 130/140 gr at 2400 and 2200 fps MV from my work w/o pressure tools and with 10x,322 and 4198 base against action function and velocity. Ok