Difference between BR Rem and 6BR Norma

[Boone]

I just bought a custom rifle in 6BR. The dies that came with the rifle say 6MM BR Rem. They R Forster Ultra die set. How much difference is there between Rem and Norma chambers. Will these dies work for both Cartridges?

 

[jonbearman]

The 6mm norma is slightly longer and I believe that there is enough room to size norma as well. However if you have a true 6mm br rem chambering you should not try 6mmbr norma brass in this chamber. Have someone or your self measure the chamber with a cerrosafe casting to see if there is enough room for the norma chambering brass to fit properly and not crimp on bolt closure and cause a huge pressure spike and damage the gun or you. Call the person you bought it from and see if he knows as well.

 

[Steve Blair]

The 6mm norma is slightly longer and I believe that there is enough room to size norma as well. However if you have a true 6mm br rem chambering you should not try 6mmbr norma brass in this chamber. Have someone or oyur self measure the chamber with a cerrosafe casting to see if there is enough room for the norma chambering brass to fit prioperly and not crimp on bolt closure and cause a huge pressure spike and damage the gun or you. Call the person you bought it from and see if he knows as well.

You do not necessarily need a cerrosafe casting to measure chamber length. The simple Sinclair Chamber Length Gauge is inserted into a shortened case, the bolt closed and the case carefully extracted and measured. This will provide a correct chamber length. The 6 BR Remington maximum case length is 1.520" and the 6 BR Norma is 1.560". Minimum chamber lengths will be about .010" over case maximums. Chambers are typically quite long but it is not worth risking the results Jon described. Measure the chamber and be safe. If you do not want to deal with it, any competent gunsmith can do it by either of the described means.

http://www.sinclairintl.com/.aspx/pid=32925/Product/Sinclair_Chamber_Length_Gage

 

[CatShooter]

I just bought a custom rifle in 6BR. The dies that came with the rifle say 6MM BR Rem. They R Forster Ultra die set. How much difference is there between Rem and Norma chambers. Will these dies work for both Cartridges?

The dies will work with both cartridges - the headspace is the same, as are most of the "critical" dimensions.

The big issue is that even though the "Specs" are the same, chambers vary a LOT in the neck diameter, and neck length/case length.

Get the chamber length gauge that sleepygator recommended - order the "243T" gauge, in case you have a tight neck.

Check the barrel near where the caliber is stamped - if there is number like 0.266" or 0.262, then you have a tight neck and will have to turn the brass in the necks for the case to fit the chamber.

It is a great cartridge, but you MUST make sure of what you have before loading and shooting it.

It would be best if you can speak with the previous owner... it will save you a lot of problems.
.

 

[GarethMarijt]

There is a very interesting series of articles about 6mm BR Norma (including differences between the Rem and Norma variants) in the May, June and July issues of http://www.targetshooter.co.uk/ (you might recognize the author ).

I certainly wished the articles had been published before I started buying new tools and equipment.

Gareth