To the OP: I've owned a Model 70 pushfeed for more than 25 years, and have used Norma, Federal, Remington, PMC, Winchester, RWS, and Lapua ammo and brass with no problems. Here's another vote for the Lapua brass.
This has been my experience with a 1986/87 pushfeed Winchester 70 XTR FWT that I bought new in 1987. It cycles all brass and factory ammo without issue. I've never shot it much, only a few hundred rounds, still working with the first lot of 100 pieces of brass that I started with 31 years ago.