A 742 is junk compared to the 750. Externally they look the same, but internally they are night and day different.
The bolt rails, gasport, and other internals are different than the previous semis from Remington. I asked a remington customer service rep what their 750 could handle in the way of ammo, and they replied 'The 750 is rated for ANY and ALL factory ammo made". That means the same ammo that would tear apart a 7400 or 742 [Light Magnum, High energy, Superformance, etc.] is completely safe in the 750. It also leads me to believe that the 750 could handle slow burning powders commonly used in 30-06 and 270 handloads.