40cal bore is the minimum here for deer and turkey is shotgun only. Small calibers dont have much use other than recreation. A PRB squirrel rifle would be the only exception.

I dont have a 40 and i have or had several of the others already. If there was a 40x357 sabot i would already own one for sure. There are a bunch of 358 rifle bullets that should work if the right sabot existed. Ive never had much luck getting them to shoot in a 45x357.

Ever since Pittman, Parker and Fury have started offering the higher BC/weight 40s, a sabotless 40 and even the 45cal with sabots is far more interesting. It fills a gap between a 45cal and the monster Swinglock 416s. Higher BC than most sabotless 45cals without the need to jump all the way up to full forming a 416.

The old 405Win was a great caliber for deer or elk and its fairly easy to duplicate those ballistics in a ML using BH209. Swap out to a conical and its very similar to a old 40-70 or 40-90. Western lists the old 40-65 WCF at 31gr by weight for a 410gr and 1290fps.