This was typical of groups with the 270gr factory load in my 375 Ruger Alaskan:
And a remarkably easy load development got me groups like this with 260gr Accubonds:
Maybe the writer was using iron sights?
In terms of acceptable accuracy- I would be happier with a very reliable rifle like a Ruger that shot consistent 2" groups at 100 rather than a tackdriver that was not as reliable.
Fortunatley most rifles these days seem to shoot around MOA with out to much trouble, so we can have reliable and accurate...