The latest from Vv/Lapua. Bullets are swaged and coated, no raw lead or typical cast bullet lube exposure to the powder. We live in a humid area, but central heat and air pulls a lot of moisture out of the room. Not real humid inside with the unit running 24-7. I guess the first response is from a HQ person named "Janne", the second response from the USA Capstone rep.

Robert,
Here is the feedback It from both LAPUA and VIHTAVOURI contacts:
Hard to say reason, but I think that this could be result of corrosion process started inside case due to some foreign material (moisture or something similar). Is it so that during loading process some foreign material have got inside case. I think powder alone will not do that. .45-70 case have such thin walls that corrosion eats through is quite fast.
And,
Sorry for my late answer; I think Janne could be right about the moisture issue.
The powder doesn’t change things that fast (six to eight years), yet I’ve seen a bunch of the “blueish/greyish” lead bullets, and sometimes even cases, kind of your pictures attached.
Humidity with impurities is probably the most common reason for this kind of results.
Since 2016, Vihtavuori has added some chemical agents to prevent case corrosion from happening. So this may have been caused by the humidity of the area you live in . Were these cartridge cases stored "bullet down" in the plastic cases?

Rounds were stored, bullet down in plastic cases. Not sure if they think that's good or bad...

Another point, if corrosion isn't a problem, why are they working to add "some chemical agents to prevent case corrosion from happening"...?

That's about as close to an acknowledgement as ya gonna get, IMO.

DF


Edited to add photo.
[Linked Image from i.imgur.com]

Last edited by Dirtfarmer; 11/21/19.