Varying reloading data


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I see that there have been questions recently regarding this subject.
Powder data versus bullet manafacturers data etc.
Vihtuavori data seems to change quite a bit as they update their load data more often than others.

My question or really suggestion is, that if I have powder from x lot 2006, then I am best to look at the 2006 load data for this powder rather than use 2017 data which may be milder/hotter than before.
Just seems to be common sense to me but some people may not of thought of this. What do you think?
Cue Laurie :D


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Never considered that. I think its worth cross referencing between the bullet and powder maker to weed out the outliers. The historic data is either likely to have changed components eg Norma, have moved from CUP to psi or been lawyerised. I don't think any change is due to powder composition unless it's a move to super short cut for example.


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It has always been advisable best practice to do a quick velocity & pressure check work up load with each new batch of powder, although in the real world I've personally never noticed any difference when swapping over to a new batch. "New data" is usually just that - not often a "new" powder with the same name, so nothing actually changes beyond the manufacturing tolerance variation & possibly storage conditions. (I always take a sniff at my old batch & the new one to compare. - Again I've not noticed any difference in the smell so all my powders must have been well kept.
I suppose the high accuracy / long range boys may see a change.- I don't shoot that well or that far (600 yards is as far as I go).



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Viht is generally pretty consistent between production lots. As far as I can see, today's versions of the more popular N100 series - N140/150/160/165 haven't changed appreciably from years back. When I change lots, I don't reduce charges these days just run a few of the cartridges loaded with the new lot past the chronograph and shoot a 100 yard group to check the wheels are still attached to the buggy.

Powders have a fair moisture content and they can lose some of it over a long period especially if the bottle is opened frequently and also if it is stored somewhere warm. (Also wise to recap the bottle as soon as possible when pouring powder and to have it in the powder measure for as short a period as possible in each reloading session.) Buying Viht N140/150/160 in 3.5 Kg bottles gives a significant saving over 1 kg measures, but it is important to decant the product into a smaller bottle and refill that as necessary infrequently rather than pour powder from the big container and return the unused portion on every loading session over a period of what may end as being several years.

This is directly counter to both powder manufacturers' and HSE advice which says dangerous goods must never be stored in anything other than the original container. This is presumably advised to avoid use of unsuitable vessels such as jam jars, also to guard against a mislabelling / mistaken identity risk in which Fred Bloggs happily jams his brass full of N140 thinking it's N160. I buy N150 and N160 in 3.5s and have kept original empty Viht 1kg or 500g containers just to use for decanted powder. They're fit for purpose (obviously) and have the proper labelling - all I change is the date and lot number to that of the 3.5 Kg bottle.

Some other makes have attracted criticism in the past for significant changes in their characteristics, either lot to lot, or changes made over time. One problem is of course that the name on the tin may stay the same, but the supplier is changed and so is the product as a result. Today's 'Accurate' loads data isn't guaranteed accurate (didn't intend that pun!) for old tubs of Czech supplied 'Accurate' powders. These powders are still available here but now under the Lovex name and with different product codes. eg the 'old form' AA-2520 is available here as Lovex DO73.6, while Western Powders in the US still sells new-manufacture AA-2520, a similar performing ball powder but made elsewhere (actually by PB Clermont in Belgium, the Ramshot manufacturer) so current 'Accurate' loading data is suspect for us and Lovex data should be used.

Some Hodgdon and Alliant grades had a reputation some years back for significant lot to lot changes. VarGet was seeing usable maximum loads change by over 2gn in hot 308 loads at one stage. The company got that sorted and you never hear of problems anymore now. I suspect the same thing has happened at Bofors which supplies most Alliant rifle grades, but several Alliant powders have been reformulated in the not so distant past, usually to make them cleaner burning (I suspect to make them Reach compliant too with manufacturers told in good time of what wouldn't be allowed from 2018). Whether that has significantly changed performance I don't know. (I did see a comment on a forum somewhere about Re10x in the 20 Practical and Tactical saying it is THE powder for these cartridges, but only the reformulated version as it works better than the original form. Whether that's true or just Internet forum nonsense ... ??

The good news is that not only has powder manufacturing technology progressed, but the WW1 and 2 era plants that had limited life left and couldn't justify major investment in modernisation have now all gone, in the west anyway. Also, the largest customer for propellants, national military organisations have become increasingly demanding in recent years. Put all these things together and propellants are pretty consistent these days and their specifications keep improving too.


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Thanks for the replies.
Over here it is possible to buy "skytterlagskrutt" which is powder, usually Bofors that has been batched and load data produced for the most popular target bullets in 6.5x55 and 308W. It is widely used by homeloaders over here and DFS shooters. It has greater batch variation and actual load data is printed on the container. Examples are N11, N19, N15 from Norma og RA4, RA11, RA15 from Raufoss. These powders are nearly the same as the N200 series/ Reloder series but some may be faster/slower batches. The powder is half the price of the pukka powder.