I've made MANY molds for subsonic use! There is no rocket science about it. The only concern is to not try to stabilize a real heavy bullet if the rifling twist isn't up to it at the low velocity. And, even with that statement, the Greenhill formula can easily be broken by a wide margin if the bullets are well aligned on takeoff so the rifling doesn't have to fight a wobbling bullet soon as it exits the mizzle.
Definately go with the 357 and a bullet weight of 200 gr using my FN profile would work fine though it will not wound very large. It will penetrate through a large hog and do a clean job of killing if punched through the heart and heavy lung areas. Put it back to the rear of the lungs where they are thin, and the kill will take a while. It will also do a fine job with nerve shots, which include spine and brain, but don't take a straight in from the front forehead shot if the hog is a big bore and his head is up, or the bone angle can deflect the bullet. Shoot when is head is down so the forehead is relitively square to the bullet and you'll bust up some bone that's very critical to his lifestyle.
If you are hoping to get a chance at more than one shot, by using the suppresser, or in not spooking other hogs in the area, forget it. In my experiance using one, which is quite extensive, an animal hit with a bullet from a suppressed gun will run farther and harder than one with a normal blast. The reason which I believe to be the cause is the fact that they can pinpoint where the shot came from exactly, whereas with a loud blast they cannot get the direction or distence of the shot quick enough to start a hard run before the kill has progressed too far for them to respond.
