Dear Dutch,
I have never shot a pig/hog with the 356 but here is my limited experience with the 356 and its sister, the 358:
358 Winchester: Shot a coyotte on a dead run going straight away at 25 yards with a Hornady 200 grain spire point at a muzzle velocity of 2600 fps. The load was 49 grains (compressed and slightly over book) of IMR 3031, new winchester brass, and a CCI-250 magnum rifle primer. The bullet entered the anus on a trajectory whereby it should have traversed the entire length of the body but the bullet did not exit. I can only assume that the bullet fragmented somewhere between a__ hole and appetite. The coyotte died instantly.
358 Winchester: Shot a deer standing broadside at 60 yards with a Sierra 225 grain pointed soft point. the bullet entered the left shoulder, destroyed it and destroyed the right shoulder as the bullet fragmented. When hit, the deer dropped straight down. He was dead before he hit the ground. No part of the front shoulders were eddible. They were totally destroyed. Great bullet performance on deer, this Sierra bullet, but may fail if a hog is hit the same way.
356 Winchester: Speer designed the 220 grain flat point for use in this caliber. It is an excellent choice for deer, black bear and hogs. I have shot several deer with this bullet, most through the lungs. I have also made lung shots with a 30/30, 30-06, 243, 7mm Mag and 358. They all ran about the same distance before expiring; 50-80 yards.
There is little choice in bullets for the 356 Winchester. Most other bullets with a flat point were designed for the slower 35 Remington.
Bottom Line: When using the 356 Winchester to hunt tough critters like wild pigs/hogs,SIZE DOES MATTER. Use bullet weights of 220 and heavier. Most shots are at close range so trajectory is not a factor.