From: "John blot", [EMAIL PROTECTED]
[snip]
My use of wadding goes back a long way and was centered
around preventing the detonation of small charges of
very fast burning powders.
[snip]
>That is very interesting, John, but my understanding of the internal
>ballistics is that it is the slow powders that are more likely to
>detonate, although the possibility is both remote and cannot be induced.
>With fast powders every ignition is almost a detonation so whether
>compressed with wadding or not these powders cannot burn any faster than
>their intended rate of combustion. What is commonly taken to be a
>detonation with fast powders is most probably a double charge.
I think you will find that the reverse is true. Fast burning
"double base" (composed of both nitroglycerine and nitrocellulose)
powders such as Bullseye are the only powders capable of detonation.
For example Bullseye is perhaps the only powder (double base) that
can be made to perform like a "high order" explosive by initiating
it with a commercial detonator - hence Bullseye's popularity with
pipebomb terrorists.
There is a distinct difference between "burning faster" and
detonation, they are two entirely different things, given the
right (wrong) circumstances - perhaps a magnum primer and a tiny
"critical mass" of Bullseye in a large case and a great deal of
bad luck, detonation could occur.
A sealed metal object filled with "ignited" Bullseye would
generate free shrapnel in the order of 600fps, the same object
in which Bullseye "detonates" would produce a shrapnel with a
velocity of around 20,000fps. So Bullseye can perform both as a
"low order" (propellant) or as a "high order" explosive roughly
equivalent to TNT.
>I use 16 grs of 2400 in 303 and that is less than one third of case full
>and in a 45-70 it will be even less.
>What you have there is a rapid drop in pressure causing incomplete
>combustion as well as unreliable ignition depending where the powder is
>at the time of ignition. If you try a bulkier powder like Red Dot or
>Unique you might find that consistency and accuracy will improve without
>wadding and without "bayonet thrusts".
>A good friend of mine used cardboard wads on top of the powder in his
>45-70 and that ringed his chamber and ruined a brand new rifle, so be
>careful and develop a load that does not require wadding.
I agree, fortunately my use of wadding has always centered around
experimenting with a very small number of rounds for curiosity
sake. For real shooting my usual ethos is that the only things
that should be in a cartridge case are a primer, powder and bullet -
no empty space or wadding.
John
Cybershooters website: http://www.cybershooters.org
List admin: [EMAIL PROTECTED]
___________________________________________________________
T O P I C A http://www.topica.com/t/17
Newsletters, Tips and Discussions on Your Favorite Topics
