difference in 6.5-284 and Norma 6.5-284

[bufflernickl]

There are three of us locally (TN USA) who want to rechamber our 6.5s to 6.5-284. I've noted that there are two different cartridges under this designation, one a Norma factory round, the other the older wildcat. However, I haven't found what the difference(s) might be.

We want to order a reamer Friday and would like to know these differences in order to make an informed decision.

One shooter is a top 1000-yd. competitor and the other two of us are hunters with long-range shooting expectations, say out to 350 yds. In either case, absolute top velocity isn't as important as accuracy. And yes, we'll order the reamer with bench-rest specs, including a tight neck. Throating will be dual-angle with a separate reamer.

Cheers/buffler

[riddleofsteel]

Over the years several manufacturers of chamber reamers have made 6.5-.284 reamers. Some were made to custom specs and those rifles are still encountered out there from time to time. However the most common incarnation of this fine round was simply the .284 case neck down to 6.5mm and the neck blown slightly forward to meet the new chamber.


This is a diagram of the Clymer 6.5-284 reamer.
In 1999 Norma developed a standard of the 6.5-284 and settled on this;


If you have an old 6.5-284 you can have die set cut by RCBS by sending them a fired case. If you are building a new rifle and plan on using Norma brass I would cut the chamber to thier specs.
In any event I would consider building you 6.5-284 on a long action rifle. It will fit into a short action but only with the longish 6.5 bullets pushed way back into the case. With a 30-06 length action you can seat the bullets way out to touch the chamber leads and utilize the full case capacity for powder. Of course if you do that you may ask yourself why not just build a 6.5-06 instead? The brass is cheaper, easier to find and plenty strong.
In my experience I have found most, but not all, 6.5-284's a touch more on the accurate side than the 6.5-06's I have been around.