55grn soft point puts them down with authority. the Post above mentions the barnes solid, also bad to the bone. Plenty enough bullet to stay together deep enough to take care of business in the boiler room or severe the spine (neck area).
I wouldn't recommend any cheap hollow points or V-max.....that's fer gophers' and stuff
The biggest problem with killing hogs is hitting them in the right place. I've seen them hit with 30-06's and run off. You have to remember their spine drops way low coming out of their shoulders into the neck. The heart is almost on the breast bone too. Draw a line from the 'armpit' to the ear and pretty much shoot anywhere along that line forward of the shoulder and it'll hit the spine and drop them.
With your quick shooting Olympic, you'll have no trouble. How you liking that thing? Been thinking about getting one myself.
In fact, by accident, I found out the 204 ruger with 45grn soft points is wicked penetrator material and poison on hogs too.
My two cent's worth! Post pix of the carnage