VV N565

[41rem]

Picked up a tin of this slow burning rifle powder, I'd like to get a starting load for the 338 RUM using the Nosler 250 grain Accubond with Federals 215 magnum primer.

The new Speer book shows a starting load of 85.0 grains of Vihtavuori N-560 (which is a tick faster than N-565) with the 250 gr. Grand Slam. Then a maximum load of 89 for 2877 fps.

Any thoughts?

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[std7mag]

Hmmm, that is interesting!
My version of the 2020 Vihtavouri reloading manual doesn't list the 338 RUM.
Jumps from 8mm to 338 Win Mag, 338 Lapua Mag, then onto 9.3mm.

 

[tirednlost]

Might give Vihtavuori or nosler a call and see if they have any info to get you started. Otherwise I’d start low, way low, and add .2 grains on each bullet until you think you’ve got max powder in there. Start at the bottom and work up until you find pressure. ‍ Hopefully one of the manufacturers can give you a start point

 

[Zero333]

You should have no problem using the 338 Lapua Starting load.

If I remember correctly,... you can reduce about 2.0 gr from the 338 Lapua's MAX and you'll be pretty close to the RUM's max with the same bullet.

But don't compare 338 LM loads with very long (non SAAMI/CIP) COAL.

Vihtavuori's load data with N-565 for the 338 LM with 250 gr bullets ranges from 90.3 to 92.1 gr.
So 88 to 90 gr in the RUM would be a safe MAX in my opinion.

 

[41rem]

Thanks Zero 333, that's a solid suggestion. I'll leverage off that 338 Lapua data.

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