We report on new high-saturation induction, high-temperature nanocomposite alloys with reduced glass formers. The amounts of the magnetic transition metals and early transition metal growth inhibitors were systematically varied to determine trade-offs between higher inductions and fine microstructures with consequently lower magnetic losses. Alloys of nominal composition ͑Fe 65 Co 35 ͒ 79.5+x Nb 4−x B 13 Si 2 Cu 1.5 ͑x=0-4͒ were cast into a 28 mm wide, 20 m thick ribbon from which toroidal cores were wound. Inductions and magnetic losses were measured after nanocrystallization and stress relief. We report technical magnetic properties: permeability, maximum induction, remanence ratio, coercive field, and high frequency magnetic losses as a function of composition and annealing temperature for these alloys. Of note is the development of maximum inductions in excess of 1.76 T in cores made of alloys with the x = 4 composition and maximum inductions in excess of 1.67 T in alloys with the x = 3 composition, which also exhibit power losses smaller than 10 W/kg at 0.2 T induction levels in 20 kHz fields. We discuss optimization of induction with chemistry and correlate the microstructures with losses.