Cast Vs Jacketed

just looked up some data on hodgdons site and its weird.....weird enough to make me question it.
the minimum and maximum loads for .45/70 at trapdoor level for a 300 grn projectile are a real head scratcher...
the cast load is going much faster with less powder???
and the min/max levels are no where near the same between the two varieties
yes jacketed will be higher pressure,understand that..but the difference is huge...and the maximum for both is quiet different too.
thoughts???

Greetings @Micky Duck,
Cast lead will, as you say, give move velocity for the same charge but loads are often held down to keep pressure low and barrel leading minimal. The cast bullets will also seal the bore better than jacketed, especially if the bore is oversize as they often are. Just treat the two sets of data as if they are for different rifles.
Regards Grandpamac.