I am looking at a rifle chambered in this calibre, can I fire Norma 6.5-284 brass in this rifle? Are there advantages/ differences between the 2 6.5-284 chambering's?

Is one "better" than the other?

The brass should be interchangeable. However, the OAL typically isn't. The 6.5-284 Winchester is often presumed to be a short action wildcat whereas the 6.5-284 Norma is a standardized designed for a long action. I tihnk a 6.5-284 Win on a 70 SA (which has a 3" mag box) would be about ideal. If I were stuck with a 2.8" mag box, I'd probably just stay with the 260....

Cooper sells the rifle and Nosler sells ammo in their "Custom" line, very pricey though. Norma, Laupa, and I believe Hornady still does, sell brass. The differance I found in the two chambers is a very slight cchange in body lenght. This shouldn`t be a problem though.
Drawings for both can be found here.........

http://stevespages.com/page8d.htm

I seriously doubt the .003" in body to shoulder length will make any difference at all. There are some gunsmiths that cut them all with the same reamer anyway, I'm sure.

The chamber is not the real difference - it's the throat and the COL.

The Norma COL is up to 3.228" The Win is whatever you can get to fit in your action/magazine.

Most short actions barf at 3.0 to 3.1 COL.

You need that long throat primarily for the 155 gr and heavier bullets used for 1000 yard competition (the 155 Sierra MK is almost 1.5 inches long!) and the long RN 155-160 grain bullets popular for 6.5 in Europe.

I'd like to have one...