which would be more effective?

[troy_mclure]

what would be a better load, a .40 180gr saboted load, or a .44 180gr saboted load, assuming same bullet construction?

which would work better terminally, and ballistically?

 

[Delmar]

I can't see a reason to assume that one would work better than the other. If the outer diameter of the sabot is the same and we know the weight is the same they should come out of the barrel at the same speed. I would suppose the question becomes, which one has a more aerodynamic shape? Can anyone tell I'm just guessing

 

[B.L.E.]

Weight and bullet style being equal, the smaller diameter bullet most likely will have a better ballistic coefficent and will retain velocity better at long ranges.
The smaller bullet will also need a faster rifling twist to stabilize it.
That's why you don't see .50 caliber sabots for .308 rifle bullets, no .50 caliber barrel comes with the rifling twist needed to stabilize such a bullet.

 

[arcticap]

The .40 180 gr. bullet has a better sectional density over the .44 180 gr. which would result in better penetration.

BTW, 20 gauge saboted shotgun slugs start out at .40 caliber before expanding in game.