Off-the-shelf brass is hideously expensive and .284 Win. brass can be hard to find.
If you likes Lapua brass you pays the price...
And you don't have to find .284 brass, just order 6.5-284 brass.
If headstamps don't matter and you aren't easily embarrassed, JB's 6.5-270 solution sounds good. That could be a creative use for .270 brass...
DF