From: Jonathan Spencer, [EMAIL PROTECTED]
>I never said that lead was lost off the bullet during
>firing did I! Only that the base could not be subject
>to melting. Of course you will there will be residues of
>bullet material mixed in with the propellant gasses
>and deposited in the bore, this happens no matter what
>the bullet material.
I'm sorry for the apparent confusion, but you gave me the impression
that you were saying that *no* lead is liberated from open base lead
bullets upon firing.
>The TMJ bullets were introduced to
>control lead release not on firing but on impact on
>steel plate backstops on in door ranges, essentially to
>keep the lead fully contained no matter what.
We'll have to agree to disagree on this one. I will, however, make this
point: upon impact with the steel plate on an indoor range, even a
jacketed bullet can break open.
>Which
>brings up further proof that the base of the bullet is
>not melted.
Don't be daft, it's proof of no such thing.
>Apparently the theory was that high lead
>levels in the air were caused by lead off the bases
>bullets. However, controlled tests by CCI with the
>new bullets revealed no impact on air borne lead levels.
Do you have any references to published works showing the effect, if
any, of airborne lead levels on indoor range in which ammunition
comprising of a lead-free primer and exposed lead based bullets were
used?.
>From this came the realization that it was actually the
>lead compounds in the primers that were actualy the
>cause of the problem, which is why CCI now produce
>lead free primers.
I agree that the reason lead free primers were developed was to minimise
lead levels on indoor ranges. However I don't yet accept your assertion,
nor will I unless you produce evidence by which I mean peer-reviewed
published papers. A pistol primer contains about 0.1 gram of material.
According to Frost(1), about 40% of that material is commonly lead
styphnate. I don't know how much lead is in lead styphnate, but even
0.04 gram (0.6 grain) per primer is a small amount of lead, but over
many shots would not be insignificant.
1. Ammunition Making by George Frost ISBN 0-935998-57-8
>The source of the atmospheric lead
>was confirmed by conducting the tests with conventional
>jacketed bullets and lead free primers.
references please
>The comparison between the heat released by a few
>grains of nitro cellulose and that released by a
>thermo nuclear device is hardly meaningful is it. The
>quantity of heat released totally different.
Of course it differs. But you seem to have missed my point: you said
temperature was irrelevant, and my point was that it is relevant.
Temperature, pressure, and time are all related in discussions over
heat.
>But I
>should point out that even so pictures of the test
>sites show that there are still remains of the steel
>towers on which the bombs were mounted.
And? Most of the steel tower has gone. The fact that a fraction
remains does not disprove my point: a high enough temperature even for a
short time will vaporise material. The survival of a fragment does not
disprove that point. But we are digressing.
>The comparison with shotgun wads is, I think, very
>valid: The thermo plastics that they are made from
>have a far lower melting point than lead and less
>thermal capacity
Maybe so - I don't know - but the shotgun operates at a much lower
pressure (hence temperature, remember) than does a rifle or pistol.
>, the operating pressures (6000 -
>12000 CUP) will not give a significantly lower flame
>temperature,
again, we're going to disagree
>a reasonably large amount of propellant
>is burned and the barrel time is quite long.
and the barrel of a shotgun has much higher volume than either a rifle
or a pistol
>But pick up a fired shot cup, do you see any evidence
>of melting on the base?
Since you ask, I have seen evidence of heat damage on shotgun wads,
especially those fired from short barrelled shotguns, and on the mouths
of shotgun cartridges fired in full length barrels. In fact, I know
someone who can examine a Winchester AA cartridge and tell you beyond
dispute whether it has been fired once only or twice or more than twice
from the heat damage pattern inside the cartridge wall. The cartridge
wall is perfectly smooth when brand new, after firing it the first time
it adopts an alligator-skin type pattern, and subsequent firings make
the alligator skin pattern smaller and finer. I believe that this
discovery was first made by Lucien Haag - one of the world's finest
firearm examiners - as part of his investigations into shotguns that had
allegedly been blown up while using a factory ammunition. This technique
enabled Mr Haag to detect that reloaded ammunition had been used when it
was alleged that new, factory, Winchester ammunition was to blame.
--Jonathan Spencer, firearms examiner
"Justice is open to everybody in the same way as the Ritz Hotel."
Judge Sturgess, 22 July 1928
Cybershooters website: http://www.cybershooters.org
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