the Federal was evidently loaded to a higher pressure.
I love to plink 7Up cans at 25 yards with my .38/.357 revolvers and a short while ago got interested in seeing whose cheap loads would group best.
I bought 500 of each of the following...
Federal "American Eagle" 158gr. LRN
Remington "UMC" 158gr. LRN
Winchester "USA" 158gr. LRN
Black Hills "Blue Box" 158gr. LRN
The Remington UMC was filthy as all get out.....it also produced groups at 25 yards off the bench less than half the size of all the other loads. 1.75 inches.
Guns used were a six inch model 19, a four inch model 586 and a four inch model 15.