VV Data shows reducing max loads over time - ??

[TomH]

Does it say on powder packaging, "the manufacturer reserves the right to make changes at any time, without notice etc..."?

[ColinR]

also, how does it work if you buy older powder stocks that people have had, or if you are one of those types that hoard it? does it have a 'produced on' date or batch code that can be understood to see when it was made, and which years manual you should be looking to?

All VV powders are dated to the day of manufacture and batch coded - not sure about other manufacturers being so clear but all will have a batch code that usually defies any tangible interpretation by purchasers.

[ColinR]

so do we need to buy a new manual every time it comes out?

Interesting point. If it is just rampant caution on the part of VV then obviously no, but if it is a change in formulation then yes. The problem is knowing and as a user of VV for God knows how many years I have never seen any notice from them about reformulation of an existing powder and need to use new data as a result.

[tackb]

I would say unless they re name the propellant then they would have to fall within certain parameters with every successive batch ?

[ColinR]

I would say unless they re name the propellant then they would have to fall within certain parameters with every successive batch ?

Seems not given the 2.1 grain difference in max load mentioned in my original post and still called N140. One would expect a suffix at least if the powder is substantially changed, such as N140n. Problem is marketing dictates and nobody likes to see change no matter what reassurances the manufacturer gives to the contrary.

[tackb]

I will continue to use proven loads in my rifles regardless.

[WelshShooter]

Currently on Vihtavuori's website they list N140 as having an energy content of 3700 J/g. Whether this value has changed over time or not will tell you whether the recipe has changed or if they are backing the loads off to be on the "safer side."

[Steve E]

Powder manufacturers revise their formula and subsequently their data at periodic intervals.
VV data has always been on the conservative side. Just work your loads up sensibly to get the velocity that you are seeking. I always advise sending ammunition for pressure testing at the Birmingham proof house. Much useful information can be gained by doing so.

[Primer]

I've recently brought the quickload software and been working on a load for my 6.5x55 and I know quickload should only be used as a theoretical guide but the max loads published in the VV manual is very conservative compared to QL, I've also looked at my 9mm and 38/357 loads and again their max loads are well below the CIP max pressure limits.