At one time, the Sierra match bullets in .30 caliber dominated rifle competitions (it may still, I do not know). However, at one time I weighed their 155 Palma match bullets that I use in my .308 Ruger M77 Target/Varmint rifle. There was that variation as you describe. It did not have an apparent negative effect on the accuracy.
Additionally, I worked up loads with Speer and Hornady match bullets and they all produced excellent accuracy, albeit with different powder charges. It would seem that all three manufacturers produce good shooting match bullets.
Sometimes you get what you pay for, sometimes you only pay more for what you get.
Three shots are not a "group"...they are a "few".
If the Bible is the literal, infallible, unerring word of God...where are all those witches I am supposed to kill?