So the overall length of the brass should be the same too?
Yes, the brass overall length specification is the same at 2.170", and you will be fine with that Lee Gauge/Trimmer.
That is the short answer. The long answer is that the 6.5x284 Winchester was a wildcat cartridge that was never adopted (to my knowledge) by SAAMI. Norma however qualified it under the European CIP standard system as the 6.5x284 Norma. You can find a
CIP approved drawing of it at this link. I suspect Lee originally made that gauge for the Winchester wildcat, and just have not changed their description to the newer Norma name.
The basic difference is the loaded overall length (COAL) is longer with the Norma. The bullet is allowed to stick out further. So, firearm manufacturers, have to provide a longer action to meet specifications. This was to overcome a significant design issue with the original .284 Winchester which was held to a short COAL to be used in a short action. You can see in the
.284 Win SAAMI that max loaded cartridge length was held to 2.800" which is the standard for short actions. The Norma on the other hand allows 82 mm COAL or 3.228". However, the basic brass cartridge is essentially the same. The ironic part is that the .284 Winchester has become so unpopular that it is hard to get brass for it. The easiest way is to buy 6.5x284 Norma brass and neck it back up to .284!
Here is the
Norma story on it, if you want to read up on it.
The 6.5x284 Norma is a very good cartridge by the way. Excellent choice for a 6.5mm caliber.
