I live in continental Europe.......... and pick one that suits US shooting practices and conditions as you'll presumably continue using it back home after the 'Worlds'. The WSMs suit our conditions and shooting format, but the 7WSM hasn't been successful in yours. US String shooting when combined with high ambient temperatures produces too much chamber and barrel heat for best results and kills barrels in short order with this cartridge. I imagine the 7PRC is a good option, as was the 284 in the 'Worlds' at Raton back in 2013.
