Because you said that the .243 is marginal at 300 yards. What typically happens now is that someone will post that it's more than adequate at 300 yards (or 400, 500 whatever). Then it, if it follows normal form, degenerates into a brawling free-for-all over the adequacy of the cartridge at whatever range, compared to this or that, ad nauseam. Eventually names will start getting called, it'll get personal and the mods will lock the thread. You should see some of the brawls that have been fought over whether .224 cal centerfire rifles (pick one, doesn't matter which) are adequate for deer. The electronic version of pools of blood has been spilled over that whole debate. It gets pretty ugly, and this time you might have started it!

Mike