RLH,
I gather that you don't like the 7mm-08;>). In all honesty, I have a friend that has shot a .243 for years and loves it. I bought one used at a pawn shop in a Win Model 70 and I hated the caliber. I know that each is to his own, but I had it in my head that this gun would shoot alot flatter and be extremely accurate. I was not happy with the accuracy at all, although it was probably accurate enough for shots to 300 yards on deer sized animals. May have had a pretty flat trajectory, but with in 300 yards there is absolutely no difference between any of the popular calibers worth worrying about. If you need flat trajectory beyond that, the .243 Win is not going to be my cartridges of choice. Wind drift, energy loss and a tiny bullet to begin with, eliminate the 243 Win for a long range cartridge for deer. That is what the .270 win and 7mm rem are made for not the .243 Win.
I rebarreled my .243 Win to a 7mm-08 with a Schillen barrel. The gun hardly kicks at all, and shoots as flat as a .30-06 to 350 yards with a "game worthy" bullet. I love mine a lot and it hardly has the ballistics of a "slug" unless you consider a .30-06 with 180 grain bullets to have that trajectory too. Now, if you handicap a 7mm-08 with an 18" barrel, then you will loose some velocity and thus loose some trajectory but that is the same with all calibers.
I will keep my 7mm-08 any day over another .243 unless I plan on doing a lot of predator hunting. FWIW this is my honest opinion. FH