Dave
I thought you were talking about mechanical wear because you keep bringing up "speed".... not pressure. Yes - you need pressure to get more speed, but you load to the same pressure with a light fast bullet as you do with a heavy slower one- so speed isn't the issue. I've burned out many 22-250 barrels and they have lasted longer with the 40 grain bullets going supper fast than they have with the 88-90 grain bullets.

I picked 243 and 6mm because I have them each (and burned out barrels in each so that it wouldn't be necessary to just regurgitate others info) It was an article that got me to experiment with them- talking about a guy that used 243 for matches and loaded his ammo to different lengths because by the latter stages of the match his throat would be worn so much-- not sure if that was Gonzales or not- either way I tested it- and loaded with same bullet- same powder at same velocity the 243 was much harder on the throat.

Also- pertaining to boat tail bullets (primarily what I use) they still direct hot gasses to the barrel and let hot cutting gases past the bullet before they seal the bore. Have you ever seen those high speed pics of different bullets leaving the barrel? The BT bullet has considerably more gasses in front of it than a Flat base- and that can't be good for the throat.