He felt obligated to say that since Lapua and Norma advertise there brass in the rag!!
I have used rem and win brass in many rifles. More often than not the hand loaded brass will hold 1/4 to 1/2 moa out to 600 yards.
I neck turned 400 pcs of rem 7saum brass a month ago, taking about .002" off the total neck dia.. I had about 15 cases that were not cleaned up completly on one side, indicating that the neck thickness varied by at least .0015 on those 15 cases. Not even close to 20%. Those 7 saum loads hold 1/3moa at 600 in my hunting/tac rifle.
My 260 has shot 2 consecutive 5 shot groups at 600 with perfect conditions under 2" using weight sorted rem brass.
My 6br using lapua brass holds better than .25 moa verticle at 600 once the barrel warms up with 8-9 shots, but that gun is scary accurate, repeatadly shooting 1.5" 600 yard groups.
every thing adds up, but it could be all for nothing if an uncorrected variable other than the brass is still present.
Now if your talking about shooting in a factory rifle, I would go with the cheap stuff.