6.4/284 is a burner, 1200 rds is the typical barrel life. Lapua is the only brass I know of, unless you neck down some old Winchester.
260 is a very good cartridge. Remington (duh), Lapua and Norma make brass.
Between the two, I'd go for 260.
6.5x284 brass is available from Lapua, Hornady, and Norma I believe? Correct me if I'm wrong.
I will speak highly of the 260rem, I love mine!![]()
If you have a long action, you could go for a 284win. Seat the heavies at mag length.
What rifle are you shooting the 260 Remington out of? What is your source of brass, .243 or .308? Do you reload?
Is it posable to have my cake and eat it too ? I noticed that the 260 hottest loads are comparable to the 6.5 284 starting loads so if I worked up a low end and a high end velocity load could I extend the barrel life of a 6.5 284 barrel if I only used the top end on windy days ?