Quick load advice: .338 Norma Mag

[Catch-22]

Hi,

 

My .338 Norma Mag is soon to be complete so need to work up some loads. I'll have a 26" barrel, 1.9-3" twist and will likely shoot 250g and 300g Scenars (though I do have other heads to try).

 

The chaps in the US favour H1000, RETUMBO and Re 33 (RS80) in this cartridge, but as those powders are hard to get, and just stilly prices, I'd really like to stay with Viht if possible. I'm also not too keen to try RS80 as I don't want to kane the barrel- though RS80 is listed as 3,850 joules, so maybe it's not too hot (like RS60 is 4,000 joules).

 

My thoughts are that N170 maybe just a bit too slow and N165 may be a little too fast for the 300g heads.

 

Anyway, if someone has QL and could help me out with some numbers for both Viht N165 and N170, I'd really appreciate it!!

 

Thanks!

[BlueBoy69]

Hi Catch-22,

 

There's plenty of load data on Vihtavuori powders suitable for the 33 Lapua Magnum and the bullet weights you mention on their website reloading page.

 

http://www.vihtavuori.com/en/reloading-data/rifle-reloading/-338-lapua-magnum.html

 

Neil

[Catch-22]

Hi Catch-22,

 

There's plenty of load data on Vihtavuori powders suitable for the 33 Lapua Magnum and the bullet weights you mention on their website reloading page.

 

http://www.vihtavuori.com/en/reloading-data/rifle-reloading/-338-lapua-magnum.html

 

Neil

Hi Neil,

Thanks for the tip - this was something I was going to do as a fall back anyway, use the 338 Lapua starting loads and work up.

Thing is, the 338 Norma Mag has about 6% less case capacity but due to the case design (shorter, longer neck, less taper) many people who use it report that the same powders used in the 338 Lapua behave differently in the Norma Mag, so I was hoping to get some QL insight if I could.

Cheers

[BlueBoy69]

D'Oh! I completely misread that, thinking it was the 338 Lapua Magnum. My bad.

 

Not much data in the reloading books I have... well nothing. Virtually nothing in the PDF guides either.

 

I can put the details in QuickLOAD if you like? As previously noted, this is purely a guide, it is not lab tested data.

[Catch-22]

Hi Neil,

That's no worries - easy mistake to make

 

If it's not too much trouble plugging in the numbers, I'd really appreciate any help. And I totally understand it's a guide only, but ball park is better than nothing.

 

Many thanks!

[BlueBoy69]

Konrad,

Here's the data as requested.

First the 250 grain Scenar loaded to CIP standard COAL.

Cartridge: .338 Norma Mag.
Bullet: .338, 250, Lapua Scenar GB488 8017
Usable Case Capacity: 97.684 grain H2O = 6.342 cm³
Cartridge COAL: 3.681 inch = 93.50 mm
Barrel Length: 26.0 inch = 660.4 mm

Powder selection criteria: 60000 psi (413 MPa); maximum loading ratio or filling of 105 %; minimum filling ration of 90%; and a burning rate factor between 0.30 to 0.50 1/bar·seconds.

Powder Type: Filling/Loading Ratio (%): Charge (gr): Velocity (fps): Propellant Burnt (%) Max pressue (PSI)

Norma MRP 2: 104.6: 94.2: 2918: 100.0: 60000
SNPE Vectan SP 12: 99.4: 95.5: 2916: 100.0: 60000
Vihtavuori N560: 96.5: 88.8: 2912: 99.7: 60000
Norma MRP: 94.7: 89.0: 2905: 100.0: 60000
ReloadSwiss RS 70: 92.0: 88.3: 2900: 100.0: 60000
Ramshot Magnum: 96.9: 95.0: 2867: 100.0: 60000
Vihtavuori N165: 99.2: 88.3: 2794: 100.0: 60000
Lovex S071: 102.5: 87.3: 2787: 100.0: 60000
Lovex D100: 105.0: 101.7: 2787: 93.1: 58956
Vihtavuori N160: 99.4: 85.8: 2786: 99.7: 60000
Vihtavuori N170: 105.0: 93.5: 2726: 95.1: 53591

Second the 300 grain Scenar loaded to CIP standard COAL.

Cartridge: .338 Norma Mag.
Bullet: .338, 300, Lapua Scenar GB528
Usable Case Capacity: 94.012 grain H2O = 6.104 cm³
Cartridge COAL: 3.681 inch = 93.50 mm
Barrel Length: 26.0 inch = 660.4 mm

Powder selection criteria: 60000 psi (413 MPa); maximum loading ratio or filling of 105 %; minimum filling ration of 90%; and a burning rate factor between 0.30 to 0.50 1/bar·seconds.

Powder Type: Filling/Loading Ratio (%): Charge (gr): Velocity (fps): Propellant Burnt (%) Max pressue (PSI)

Norma MRP 2: 100.9: 87.4: 2664: 100.0: 60000
SNPE Vectan SP 12: 96.0: 88.8: 2663: 100.0: 60000
Vihtavuori N560: 93.1: 82.5: 5.34: 2660: 100.0: 60000
Norma MRP: 91.3: 82.6: 5.35: 2646: 100.0: 60000
Ramshot Magnum: 93.6: 88.3: 5.72: 2615: 100.0: 60000
Vihtavuori N170: 105.0: 90.0: 5.83: 2591: 98.1: 59660
Lovex D100: 102.4: 95.5: 6.19: 2582: 95.6: 60000
Vihtavuori N165: 96.0: 82.3: 5.33: 2548: 100.0: 60000
Vihtavuori N160: 96.3: 80.0: 5.18: 2545: 100.0: 60000
Lovex S071: 99.1: 81.2: 5.26: 2537: 100.0: 60000

Hope this helps?

 

As always, this is just a guide, not defacto reloading data.

Neil

[Catch-22]

Thanks Neil - this is very very helpful. I may need to explore some of the other powder options listed beyond VV.

 

Many thanks again!