Yes. For some reason, this cartridge never really gained popularity. It is almost identical in ballistics to the 6mm Remington, and people say that it is a barrel burner (which, the same people say that the 6mm Rem is "ohsomuchbetter", so you can guess how valid those claims are)
The .243 WSSM is a great cartridge, on paper, i have never shot one, but the ammo is more $$$, less available, and fewer bullet options. Stick with the regular .243 unless you reload, and then only if you can stock up on a LOT of brass. If you want to keep shooting this thing just in case it goes down the drain.