Thread: Lapua vs Norma brass - your predictions ?

Got Norma and Lapua brass in 7-08.

Both have been neck turned, flash hole deburred and sized the same.

Using the same primers, load and carefully sorted (bearing surface) projectiles...

Your predictions about different (if any) point of impact ?

My Lapua 6mmBR brass holds more powder than the equivalent Norma case. If the same holds true for 7mm-08
brass then I predict a difference in pressure & (maybe) poi.

My 2c

Have had same issues in my 6br
The norma brass is alot thicker.
Pressures go up , cratering the works
I threw mine out and stick with lapuas now,

Originally Posted by NZ_noddy

My Lapua 6mmBR brass holds more powder than the equivalent Norma case. If the same holds true for 7mm-08
brass then I predict a difference in pressure & (maybe) poi.

My 2c

Recently done some water capacity numbers for 6BR brass formed into Dasher -
Norma cases 40.45 cc
Lapua cases 41.54 cc
The Lapua case weight averaged about 6 grains lighter.
Loaded into Quickload it sees these values as significant differences.
Actual velocity tests with the same powder charge however still to be done to confirm calcs.
Then simply a matter of plugging into Shooter.

Originally Posted by zimmer

Recently done some water capacity numbers for 6BR brass formed into Dasher -
Norma cases 40.45 cc
Lapua cases 41.54 cc
The Lapua case weight averaged about 6 grains lighter.
Loaded into Quickload it sees these values as significant differences.
Actual velocity tests with the same powder charge however still to be done to confirm calcs.
Then simply a matter of plugging into Shooter.

Hey @zimmer, off topic a bit, but how do you find the Shooter Ballistics?

Originally Posted by Double Shot

Hey @zimmer, off topic a bit, but how do you find the Shooter Ballistics?

Very good, when I first got it. I have a real old Ipod with Shooter, Ballistic AE and BulletFlight L2 on it. They all give virtually the exact same results but Shooter is a bit more friendly to use. Installed Shooter on my tablet when I first got it and Shooter just kept crashing. Got a refund under the 15min offer. No response/support from the app writer so gave up putting it back on the Android. Use Strelok on my tablet or JBM on my desktop. Bryan Litz's too expensive.

Apologies ebf

I'll be interested in the result, I think the Norma will have more case capacity and thus a lower pressure.

What distance are you going to test at ? If it is close not sure you will see any difference.

James.

Have not done a water capacity measure yet. But primed caes I get:

Norma : 166-169gr
Lapua : 178-179gr

Distance will be at least 225yds, probably a fair amount further if I can arrange it.

You will get a velocity difference.
How much will depend on how far out you will see a POI difference.
If not much you won't see it at 225.

10grns different in weight is a fair bit of brass. I use Norma. It doesn't last as long as Lapua but I get better results on initial forming of the brass.

Sent from my SM-G935F using Tapatalk

Norma will have more case capacity than Lapua, if you are running maximum in Norma the Lapua with the same load will generate more pressure and may change impact. Loads under Max should be the same in both cases IMO.

Did some chrony tests this morning.

Lapua is giving 2625 fps, while Norma is giving 2595 fps

To put it another way 40.7gr of 2208 in the Lapua gives the same velocity as 41.0gr in the Norma cases

Originally Posted by ebf

Did some chrony tests this morning.

Lapua is giving 2625 fps, while Norma is giving 2595 fps.........

Is that with an average of at least 5 shots for each lot of brass?

Originally Posted by 10-Ring

Is that with an average of at least 5 shots for each lot of brass?

Yup

Very interesting, even with the slightly reduced load in the Lapua it still seems to build a bit more pressure.

At just over 770 yards the Norma cases needed 23.0 MOA elevation, but but the Lapuas only needed 21.5.

Thanks to Doc Watson for helping with some pretty interesting wind calls this afternoon

If that followed my 303brit brass the volume difference is like 1~1.2 grains of 2208.