From: ahahma@utu.fi (Arno Hahma)
Subject: Re: .308 ammo (fcty powder choices)
In article <CDrp33.BAp@fc.hp.com>, Bart Bobbitt <bartb@hpfcla.fc.hp.com> wrote:
#Dion Hollenbeck (hollen@megatek.com) wrote:
#: turns out to be XXXX". He then went on to explain that a manufacturer
#: *intends* to make a certain powder, but until the entire lot is
#: finished and *tested* they cannot be sure what they have made. Once
#: testing is done, they can tell exactly what powder they came
That is right. It is very difficult to make a powder exactly right,
that is to match your expectations. That is why they have to test the
result for each lot of powders. However, you still can come close to
what the powder should be and the final tuning is done by mixing
powders of different speed (or simply from different lots) to get the
burning characteristics to the specifications. The more experience and
skill the powder makers have, the less they have to mix powders and the
more uniform the product will be.
Also, the larger the lots the more uniform powders you can expect. That
is why Russians make excellent powders - they probably can make such
huge lots, that would never pass the safety considerations here...
#: it. They sometimes even have to junk a lot of powder because they
#: created a powder which was extruded into one form, but is completely
That happens sometimes, when the factory has problems with the
process. Then they either burn the powder or reuse it for ball powder
manufacture or even for extruded powders, if the surface coating had
not been done yet.
#happens with ball powder. Folks I'm in touch with who use ball powder
#report a greater variance between ball powder lots than extruded powder
That is correct, too. Ball powder process is much less controllable
than the extrusion process. The ball powder is surface treated in a
water suspension (usually) and this stage is very critical. Change
anything even slightly and the powder will end up far out of your
spec. Things like temperature, solvent content, time of addition of
the chemicals, mixing speed and time, specific gravity of the
materials, amount of the powder present at one time in the reactor all
affect the burning characteristics. These parameters are hard to
control precisely. Then you need some luck, too ;).
#suppose lot to lot variances could cause one type's lot to be close
#enough to another type to be labeled as such.
I think no powder factory will accept "close enough" but it has to be
exactly, what the specs tell. This is achieved by mixing different
lots, see above.
#So, I'm going to call three or four powder companys and ask 'em what their
#processes are to make and qualify a given powder type. Then I'll put their
That would be nice! Different factories have different policies how to
get consistant results. It would be nice to hear, how they do it - do
they make all sort of powders as mixtures of a few base powders or do
they make them as a single lot fine tuned to the specifications.
ArNO
2
From: ahahma@utu.fi (Arno Hahma)
Subject: Re: new powders
Organization: University of Turku, Finland
In article <Pine.3.89.9404092037.B24271-0100000@plains>,
Myron A Faa <faa@plains.NoDak.edu> wrote:
#Can anyone give me any information on the new powder from VihtaVuori
#of Finland?
You mean the N500 -series? I'd say it will take at least a year, before
they are shipping the powder in quantity. The new powder line is still
under development and they surely want to have it well finished before
they release it.
#It is suppose to give increased velocities without increasing
#pressures. It is talked about in the April issue of Guns and Ammo.
That is true. The burning characteristics have been changed to yield a
much flatter pressure curve. That will allow you to load more powder
without increasing the peak pressure and therefore, you will also get
more velocity. In addition, the N500 -series powders are somewhat more
energetic, than the present handgun powders.
ArNO
2