I have a 308 myself, but have always liked the 243 round. if someone made an assault style weapon in 243, I think it would be a good seller. I know I'd buy one.The .243 is a fine deer caliber but a .308 would be a much better choice for the survivalist. The .243 is actually just a necked down .308, but .308 ammo is more common and comes in a much wider variety of bullet weights and styles. The .308 can also be used to take larger game like elk and moose, whereas the .243 is mainly suited to deer and medium sized game. If you are going for a semi-auto rifle then you should definitely get a .308 because of the availability of surplus 7.62 NATO ammo. Even if you are getting a bolt action I would recommend it over the .243.