Varget variations

[Snuby642]

Advise on Varget needed.

All my dealings with Varget mostly in 308 have found safe accurate nodes
at 95 to 100% of "book max".

Working up new 308 / 165 SGK had heavy bolt lift at 95% and up (not even crunching).
Checked brass case capacity, coal, bto, bump all normal.

Is it common for Varget to vary 5% or more by lot?
None of the rest of the jugs did for me but only a couple year sample.

Maybe starting at 95% book is a bad habit but seemed like everything went into that
slot for me so far.

308 20 inch
165g SGK
43g Varget book max, heavy bolt lift at 41.0 (95%)
BTO 2.100 0.045 jump
0.0025 bump
brass fc / cbc volume measured the same although cbc was 2% heavier

 

[waveslayer]

It can, that's why most of us buy 8lbs plus at a time

 

[Superjet]

Absolutely can. I’ve seen considerable variations in 1 pounders that are in the same lot.

 

[nn8734]

“Book max” is largely arbitrary. Your rifle is telling you everything you need to know. You’re at pressure with that charge weight with those components and that lot of Varget. Back off like .5 grain or so and work on seating depth to dial it in.

 

[TRPrecision]

One of the girls 6br's had been dead stable on a diet of 30g varget @ 2800-2805 very consistent over 2 different lots of Varget. Ran out and switched to a new lot, the same charge bumped it to 2840-2845. Was not enough to cause a pressure issue, but put things a good bit higher at distance.

 

[Snuby642]

Good I feel all better now.

Would by 8lb if I can get hands on them.
Used to but lately 3-4lb at a time.

I have always been conservative on loads and don't even like to compress them
so this was a little surprising.

 

[6.5SH]

Perhaps put some of your new lot in a sealed container with a 50% 2 way humidor pack (Ex; Boveda) for a few days then try that load again.

 

[sinister]

Thales - ADI had a fire a few years back that damaged the original powder manufacturing line and contributed to a worldwide shortage of Australian-sourced Hodgdon powders (Varget, Retumbo, 8208, etc.) for a while.

They built a second line with the plan to dismantle the first once they were fully operational. Once the second line was functional (but wasn't to full-service) they started demolition of the first -- except the second started having quality control issues to where they would accept one good lot for two others that had to be scrapped.

It seems they're just now starting to get lots into the country if you can get by the shipping supply chain bottlenecks.

 

[ShtrRdy]

Something else I've learned about recently is humidity can change the moisture content of the powder which will change density and burn rate. Do you live in a dry climate?

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

 

[Snuby642]

Dry climate, no only in the dead of winter.
Three different load dates probably only one during low humidity.