Vihtavuori powder

[Roughrice]

What is this?

Simple version.
It's a flame chart.
Think of it as heat units given off when the same volume of different powders is ignited in the same space and environment.

 

[K.E.C.]

I'm looking for some that would be good for 7mag-7prc.

Try 560 or 565 for 7mm or prc. edit I have switched to Vv for just about everything .

 

[marc357]

They stated the older the powder gets the hotter it gets

This is true with all powders. Depending on the climate you live in. In a high humidity environment powders absorb moisture, slowing their burn rate, and in a desert environment they dry out, increasing their burn rate. I have experienced this, in both environments.
Here's a rabbit hole for ya:

How does humidity affect powder?

You may have heard about a relationship between humidity and bullet velocity either in a book, on a reloading forum, or from a crusty benchrest shooter right after saying they get better ES/SD&#821…

chronoplotter.com

I have gone to using the Boveda packs and a small Bluetooth monitor to control/ stabilize powder moisture levels.

 

[Silver_Is_Money]

What is this?

The KiloJoules of Energy contained within each Kilogram of powder. It has nothing to do with burn rate or charge weights.

 

[sendero72]

I'm looking for some that would be good for 7mag-7prc.

I have 2 lbs of N570 that I don't need. I paid $50 per lb. Glad to sell it.

 

[Alb Greg]

Been using N550 for years in my .300 WSM and will keep using it. Elk in freezer almost every year. 62.5gr N550 over 180 gr Nosler Partition.

 

[Knight]

Some years ago I read an article that one of these powders can turn acidic with age and can self ignite. I don't remember what number so I discontinued using Vihtavuori powder altogether.

 

[VinceMule]

Heat Index for the respective powders.

 

[Knight]

I clearly remember looking into a bottle and noticing a slight yellow hase on the powder and it had a acidic smell. This was about 38 years ago. I'm sure it has been corrected by the manufacturer and not to worry any longer. I personally continue using the most common brands IMR etc.

 

[deputyrpa]

What is your barrel length? I find N565 just about perfect for a high density load with 100% powder burn for 175s out of my 22" barrel.

 

[Cnkhunting]

It's 26" and I'm using h1000 and rl26 with my loads now. Thinking of trying the b powders and get a few pounds on hand that I know work just to have back up

 

[deputyrpa]

It's 26" and I'm using h1000 and rl26 with my loads now. Thinking of trying the b powders and get a few pounds on hand that I know work just to have back up

The you can probably go with a slower powder like N570, but you'll most likely have a full case with a bit of a crunch at max pressure.

 

[Gary in MD]

N-555 3750 KJ/Kg
N-550 3950
N-560 3900
N-540 4000
N-570 4000
N-140 3600
N-170 3700
N-150 3790
H-4350 3900
Varget 4000
H1000 3780
H4831 3850

For comparison via GRT

Where is N-160 ?

 

[Seabeeken]

Just didnt include it