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VV Data shows reducing max loads over time - ??
Posted: Mon Mar 23, 2015 10:03 pm
by ColinR
In the 2nd edition VV reloading manual (1995) the max .308 load for a 150 gr LockBase with N140 was 46.8. In Edition 7 the same bullet and powder has a max load of 44.7 and shows this as a 'full case'. Same seems true for other combinations. Why is this and does it mean older data is now irrelevant/over pressure?
Re: VV Data shows reducing max loads over time - ??
Posted: Mon Mar 23, 2015 10:19 pm
by The Gun Pimp
Just means VV are becoming more cautious............
Re: VV Data shows reducing max loads over time - ??
Posted: Mon Mar 23, 2015 10:54 pm
by ColinR
The Gun Pimp wrote:Just means VV are becoming more cautious............
But is the original data still valid? Beyond caution has anything else changed that would indicate upping the current max load by over 2 grains exceeds a safe margin?
Re: VV Data shows reducing max loads over time - ??
Posted: Mon Mar 23, 2015 11:24 pm
by phaedra1106
Has the powder formulation changed over the last 5 years?. If in doubt start at the lowest published load and work up from there.
Re: VV Data shows reducing max loads over time - ??
Posted: Tue Mar 24, 2015 12:05 am
by StanDeasy
VV reformulated their commercial propellants back in the 90's when they removed the flash suppressant. The new-spec N140 was a noticeably bigger grain size than the old, which is why some loads are now shown as "full case".
Re: VV Data shows reducing max loads over time - ??
Posted: Tue Mar 24, 2015 12:18 am
by DaveB
Actually, I think this is part of a trend. Though I have never confirmed it myself, I have read a number of articles in various US shooting magazines that mention that newer issues of reloading manuals seem slightly more conservative when it comes of starting and maximum loads, than their versions from 20 or even 10 years ago.
Re: VV Data shows reducing max loads over time - ??
Posted: Tue Mar 24, 2015 7:46 am
by M99
I had this discussion recently with an ammunition manufacturer and someone who knows about powder!
Their take on it was that the changes are down to the changes in the manufacturing process and that as a producer of ammunition they had noticed the changes in their end product.
Follow the guides, they follow the changes to the powders!
Re: VV Data shows reducing max loads over time - ??
Posted: Tue Mar 24, 2015 8:07 am
by ovenpaa
Is it entirely due to changes in the make-up of the powder or is there a degree of fear of litigation thrown in for good measure these days?
Re: VV Data shows reducing max loads over time - ??
Posted: Tue Mar 24, 2015 8:52 am
by tackb
so do we need to buy a new manual everytime it comes out?
Re: VV Data shows reducing max loads over time - ??
Posted: Tue Mar 24, 2015 9:01 am
by bradaz11
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?