this is the thing with the black art of reloading
there's lots of ideas to achieve the same goal
i just found it unnecessary with lapua to anything (i do chamfer forgot to mention this) i am getting .25 moa with my 223 with this method
its lapua i've got and a lot of people have said there is very little triming with this brass.but im new to the reloading .must say that the cases i've got seen very good ,not found damage as yet to them,but being loose in the box seems not a good idea.
I have found you have to resize all new brass even Lapua my usual choice.If you don't you may notice differences when seating bullets. This is due to differing neck tension on the bullet. Usually it will be one that seems to require no effort to seat the bullet ( not that any should require much effort). Lack of neck tension will usually result in a flyer I learned this lesson from experience.
Nosler custom brass, I find has zero requirements as to prep before loading, apart from a visual check for transit damage,...... at the other end of the scale I have some Winchester 300 WSM recently necked down to suit 7mm WSM, & some Remington Peters 7mm WSM , These trim to length swarf samples show the difference in ductility of the two brands of brass, The Remmy is the first pic.