What is the degree of accuracy at 1000 yards of a .308 Norma magnum?

Norma makes ammunition, not rifles. Accuracy will depend on WHICH rifle is firing the .308 Norma Magnum cartridge. Many are Schultz and Larsen products, others are hand built conversions. Accuracy will depend on whether it is a target rifle or a lighter sporter grade rifle. The round has pretty much been bypassed by the .300 Winchester Magnum cartridge.