I’m new to this game and recently built a 6mm BR Norma. While researching load data, I noticed a sizable difference between 6BR Remington and 6BR Norma loads. For example, using the latest Sierra Manual for a 107 Gr Sierra HPBT with Varget, the 6BR Norma starts at 26.0 grains and stops at 27.5 grains. Whereas the 6BR Remington starts at 27.4 grains and stops at 28.9 grains Other than the neck length, are they not essentially the same cartridge?
6BR Remington v. 6BR Norma
- Thread starter litig8or
- Start date
All the 6MM BR Norma is a redevelopment of the 6MM BR Remington. All Norma did was to modify the throat to adopt using the 105-107 grain match bullets and they respecified the cartridges overall length and they changed the twist rate to an 8TW from what Remington was using and what was adopted in 88.
I agree and will give your suggestion a go.
Thanks
From what I read a few years ago. The Rem 6BR Rem cartridge was popular in Europe for 300 meter competition. Lapua wanted to make the cartridge brass but Rem held the Patent and wouldn't allow them to make the case. Lapua made enough small changes to the case dimensions so it avoided the patent and was patented as a new caliber. I think there was about 3 small changes in dimensions. It's been a long time since I read the article but I think the changes were only a few thou.
Making the throat longer for the heavier bullets. I assume that is the reamer dimension and not the cartridge dimension. The cartridge design is patented but you can make the reamer to any dimension. I am sure the body diameter was increased a small amount in the 6mmBR Lapua. They needed the change the case dimensions enough that the it would qualify as a new cartridge design and not a copy. I don't know if you can chamber a 6 Lapua in a 6 BR Rem? I would think there is a very small difference in case capacity for the two cartridges. It doesn't really matter since no-one with common sense would buy the Rem version. Pretend it doesn't exit.
Last edited:
BoydAllen
Gold $$ Contributor
Fellows, there is a lot more to this than previous posters have led you to believe. Here is a post that was put up on this site back in 2007 by Al Nyhus that lines out pretty much everything.
"Glenn, here's a brief history of the 6BR.
-The original Remington 6BR was in fact .040 shorter than todays widely accepted version of the 6BR, which is the Lapua case stamped 6BR 'Norma'. Early chamber length was 1.520. Later Remington 6BR chambers had the neck lengthened .040 to 1.560.
-The original Remington 6BR brass was smaller at the back than the current Lapua case. This is because originally there was no factory brass for the 6BR chamber. You made cases for the BR chambers from the Remington URBR case...which was a full length 308 case with small primer pockets but with large flash holes. Very thin walls and some agressive annealing as they came from Remington made this radical case forming possible..if not always perfect in actual use. This URBR brass runs about .466 at the back end. The original Rem. 6BR chambers ran around .468 on the back end versus the current Lapua chambers that run in the area of .473 at the back. When the chamber spec. was changed to 1.560, Rem. released factory 6BR cases that were .040 longer than the original chambers but still keeping the original base dimension that was established when the URBR brass was the parent case. This way, the factory brass could be used in either chamber by just shortening the necks .040 for those guns with the original 1.520 chambers.
Unfortunately, the original 6BR developed a bad reputation for sticky cases, hard extraction and inconsistant neck tension. This was no fault of the case design itself, but rather a result of the extensive case forming that had to be done to make the 308 URBR case fit the 6BR chamber..remember, there was no factory brass at that point. Most BR shooters were only neck sizing at that point in time and the combination of difficult case forming, the poorly understood need to reanneal these cases after being formed from the URBR brass, minimal case resizing being done, dies that were improperly dimensioned, etc....all combined with shooters trying to push the new case design to very high pressure levels....gave the 6BR a bad reputation from the start. When the PPC cases came along, the 6BR was dead in the water from the avarage BR shooters point of view.
It's possible that if Remington had made factory 6BR cases available from the start, eliminating the need for shooters to make their own from the 308 URBR brass,the 6BR may well be the dominant 100-300 BR case today rather than the 6PPC.
So, basically here's how it shakes out:
-Early 6BR/22BR chambers: 1.520/.468 back dim.,from URBR brass)
-Later 6BR/22BR chambers: 1.560/.468 back dim.,Rem. brass)
-Lapua 6BR Norma chambers: 1.560/.473 back. dim.,Lapua brass)
Why Lapua chose to change the dimensions I'm not sure. But it resulted in a very heavy duty case with plenty of material around the primer pocket to stand up to very severe use.
Why die makers haven't discontinued the 'Rem 6BR' designation on their dies made for the Lapua case remains a mystery to me. I've worked with a few current 6BR dies from several mfgs. and they all have been dimensioned to work with the Lapua specs. I know that Wilson redid their dimensions quite a few years ago to work with the Lapua case, as did Redding.
How the 'Norma' designation came into play on the Lapua case is interesting...European guidelines call for their cartridge specs. to include the throat, thus the 'Norma' designation on the case...which has nothing to do with the actual case dimensions itself.
This isn't meant to be a complete treatise on the eveolution and history of the BR case..just a quick overview.
Bottom line: If you want to build a 6BR, use a reamer dimensioned for the Lapua brass and all will be well. Honestly, I can't imagine that there are many people out there chambering for the 'original' 1.520 or 1.560 Remington chambers.
Hope this helps. -Al"
"Glenn, here's a brief history of the 6BR.
-The original Remington 6BR was in fact .040 shorter than todays widely accepted version of the 6BR, which is the Lapua case stamped 6BR 'Norma'. Early chamber length was 1.520. Later Remington 6BR chambers had the neck lengthened .040 to 1.560.
-The original Remington 6BR brass was smaller at the back than the current Lapua case. This is because originally there was no factory brass for the 6BR chamber. You made cases for the BR chambers from the Remington URBR case...which was a full length 308 case with small primer pockets but with large flash holes. Very thin walls and some agressive annealing as they came from Remington made this radical case forming possible..if not always perfect in actual use. This URBR brass runs about .466 at the back end. The original Rem. 6BR chambers ran around .468 on the back end versus the current Lapua chambers that run in the area of .473 at the back. When the chamber spec. was changed to 1.560, Rem. released factory 6BR cases that were .040 longer than the original chambers but still keeping the original base dimension that was established when the URBR brass was the parent case. This way, the factory brass could be used in either chamber by just shortening the necks .040 for those guns with the original 1.520 chambers.
Unfortunately, the original 6BR developed a bad reputation for sticky cases, hard extraction and inconsistant neck tension. This was no fault of the case design itself, but rather a result of the extensive case forming that had to be done to make the 308 URBR case fit the 6BR chamber..remember, there was no factory brass at that point. Most BR shooters were only neck sizing at that point in time and the combination of difficult case forming, the poorly understood need to reanneal these cases after being formed from the URBR brass, minimal case resizing being done, dies that were improperly dimensioned, etc....all combined with shooters trying to push the new case design to very high pressure levels....gave the 6BR a bad reputation from the start. When the PPC cases came along, the 6BR was dead in the water from the avarage BR shooters point of view.
It's possible that if Remington had made factory 6BR cases available from the start, eliminating the need for shooters to make their own from the 308 URBR brass,the 6BR may well be the dominant 100-300 BR case today rather than the 6PPC.
So, basically here's how it shakes out:
-Early 6BR/22BR chambers: 1.520/.468 back dim.,from URBR brass)
-Later 6BR/22BR chambers: 1.560/.468 back dim.,Rem. brass)
-Lapua 6BR Norma chambers: 1.560/.473 back. dim.,Lapua brass)
Why Lapua chose to change the dimensions I'm not sure. But it resulted in a very heavy duty case with plenty of material around the primer pocket to stand up to very severe use.
Why die makers haven't discontinued the 'Rem 6BR' designation on their dies made for the Lapua case remains a mystery to me. I've worked with a few current 6BR dies from several mfgs. and they all have been dimensioned to work with the Lapua specs. I know that Wilson redid their dimensions quite a few years ago to work with the Lapua case, as did Redding.
How the 'Norma' designation came into play on the Lapua case is interesting...European guidelines call for their cartridge specs. to include the throat, thus the 'Norma' designation on the case...which has nothing to do with the actual case dimensions itself.
This isn't meant to be a complete treatise on the eveolution and history of the BR case..just a quick overview.
Bottom line: If you want to build a 6BR, use a reamer dimensioned for the Lapua brass and all will be well. Honestly, I can't imagine that there are many people out there chambering for the 'original' 1.520 or 1.560 Remington chambers.
Hope this helps. -Al"
Boyd is right on the money! I personally own a 6BR Remington and a 6BR Norma and I bought new Lapua brass for it and it would NOT chamber. Gary
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