Will the pressure change? Yes
Will the cartridge obtain "excessive" or "dangerous" pressures but adjusting the OAL? It could
Yes, but the "excessive" or "dangerous" pressures would occur with an increase in OAL not a decrease. The shorter the OAL the less the pressure, the longer the OAL the higher the pressure.
And that's dependent on the throating. If you seat into the rifling, yes.
Anytime the cartridge has more capacity, you lower pressure, all else being equal.
