Lapua Brass

[Edward]

What's the difference between the blue box and gold box brass?

 

[dkhunt14]

Some say the Blue box has thinner necks. I don't know I still have a bunch of gold box. I have also heard the blue box blows shorter fireform length. Matt

 

[jonbearman]

I have measured and it is only slightly thinner ,like .002 thou total at best.

 

[dmoran]

According to Kevin Thomas (Lapua USA) there is no difference, just that the boxes got changed from cardboard (gold) to plastic (blue), and has stated: "That depends on whether you like gold boxes, or blue boxes. The brass inside is exactly the same, either way."

To me and several others (including metallurgist), there was more.

 

[artbosco]

The Gold Box is no longer made.

 

[dedeadeye]

Matt, all the brown box brass I have is thicker in the necks. It will normally clean up at .0127 and forms (for me) longer than the blue box when forming the Dasher. In my old .272 Krieger I had some brown box form as long as 1.567. The blue box I have (1000) will clean up at .0117 and has never formed over 1.552 in the same .272 chamber. Most blue box form at 1.546, again with my method. So, identical chamber for both, but very different form lengths. Roger

 

[dkhunt14]

That's good info there Roger. That is the same as I heard from other Dasher shooters. I just couldn't verify because I don't have any Blue box brass. Matt

 

[johara1]

Matt, I have a 1000 blue box with .011 neck thickness and 1.555 long and it cleans up at .0102and i FF. at 1.550+ and the flash holes are all over the place…. I for one will be glade to see Norma Dasher cases……… jim

 

[jonbearman]

The .2704 reamer turned out to be a pain for me as I had to turn my brass for a no turn neck.I am sorry I sold my .272 reamer.

 

[dmoran]

Matt -
Back in 2009 or so, I loaded both brown box and blue box up with an identical fire-forming load and shot them "round-robin".
Here is what I saw/results:
- the accuracy was nearly the same at 450yds
- the POI and velocity were both a little lower with the blue box
- 1.556 to 1.560" blow lengths with the brown box
- 1.536 to 1.546" blow lengths with the blue box
- primer pockets were loose with the blue box (load was to hot for them)
- primer pockets remained tight and nothing hurt with the brown box (load was fine)
- the blue box would hardly grow any longer in fallowing cycles
- the brown box grew for a couple cycles before settling down
In my opinion, there not even close to being the same, but both work fine, just have to really dial things in right when forming 6Dasher's from the blue box in comparison. Where as the brown box brass was real easy and very forgiving for me to blow consistent and long enough 6Dasher's from....
Donovan

 

[22BRGUY]

According to Kevin Thomas (Lapua USA) there is no difference, just that the boxes got changed from cardboard (gold) to plastic (blue), and has stated: "That depends on whether you like gold boxes, or blue boxes. The brass inside is exactly the same, either way."

To me and several others (including metallurgist), there was more.

Thanks as always for info Donovan and others. Out of curiosity Donovan,what did the metallurgist say if anything important? thanks

 

[dmoran]

Thanks as always for info Donovan and others. Out of curiosity Donovan,what did the metallurgist say if anything important? thanks

It was on here (AccurateShooter) some place from a few years back, I just can't find it (sorry)..., but a private guy independently tested brass to several different brands and cartridges, including both brown box and blue box 6mmBR brass, and found them to be 2 different alloys of brass all together.
The topic got argued hard and beat around some, so maybe it got deleted, I'm not sure. I think there was even a "Daily Bulletin" on it with his metallurgy reports.
Donovan

 

[dedeadeye]

Donovan, good information as always. Roger

 

[mikecr]

Yes, great report Donovan

 

[FatBoy]

I have both old gold box and new blue box loaded on the table. I do not neck turn, etc. I measured four of each and all eight loaded neck diameters are exactly the same.

 

[goodi]

follow the following link to the brass spectrometry report referred to in the above discussion

http://www.accurateshooter.com/technical-articles/x-ray-spectrometry-of-cartridge-brass/

cheers
dg

 

[johara1]

Dave, That is what i was looking for. I see Lapua blue box and Norma are about the same ……… jim

 

[Ghansen]

Given those results, and historical data about how good the gold box formula lasted I wonder why the change? Copper costing more than zinc, and 20% more copper at that!

Referring to the editors comment in note 2 of the article, what is the longevity comparison (for those who have used both) between blue box v gold or brown box varieties? (and maybe any other subtle differences)


from article:-
2. The range of Copper/Zinc ratios suitable for use in cartridges intended for reloading is 80/20 to 70/30. Above 80% copper, the resulting case would tend to be too soft and difficult to attain the distribution of hardness desired (harder at the base and softer at the neck). Below 70% copper the resulting case would tend to be too hard, would work harden too quickly and require frequent annealing. [Editor: That said, the 'brown box' 6mmBR Lapua brass, with 62% copper/36% zinc content, enjoys an unrivaled reputation for both accuracy and its ability to perform well after a dozen or more reloading cycles. We know 30BR shooters who have shot the same old-style Lapua brass (6mmBR parent case) more than 50 times. So maybe the "expert" view needs re-thinking.]

 

[CSM19Z5M]

The difference is they changed the color of the boxes. They discontinued the gold cardboard type box and replaced with a blue plastic box. I think the so called difference that some people swear to between the two is just a perceived difference rather than fact. Lapua says they are the same brass just different box. You can find very slight variations in any brass, even Lapua's, from lot to lot. It's called manufacturing.

 

[snakepit]

Lapua says they are the same brass just different box.

That is not what they said. The blue box brass was purposely made with thinner necks as Lapua's loaded ammo was too close to CIP maximum diameter. That was posted here numerous times by Kevin Thomas from Lapua and measured by many of us. Look it up before you spread your delusions as the truth.

I do not have a dog in this fight but in the Reloading Forum Topic: "Gold Box Vs Blue Box Lapua Brasses" reply #3 on 10:02 AM, 04/07/14 Kevin Thomas of Lapua says and I quote "That depends on whether you like gold boxes, or blue boxes. The brass inside is exactly the same, either way. Why hasn't this mythology died a natural death yet?"