If you like short action calibers you could go witha .308 or 7mm-08. These calibers are descent flat shooters and offer a wider variety of bullet choices than the .243 The .308 or .30 caliber offer bullet weights ranging from 100 gr. all the way up to 200 gr. and the 7mm-08 range is pretty much the same up to 175 gr.

Although I would suggest staying in the mid range weights due to the lower velocity of the short action you may not have enough punch to properly expand the heavier bullets.

Just my .02 cents