From: [EMAIL PROTECTED]
I'm still not convinced that propellant gasses are
responsible for melting any significant quantity of lead
from the base of a bullet. I used to think that this was a
major cause of leading but now I'm not so sure.
It seems far more likely to be down to bullet sizing and
alloy type rather than the lead actually being melted by
the propellant.
I would think that any bullet that is larger (even by a very
small ammount) than the bore or cylinder mouth is very
likely to leave an ammount of it's mass behind, especially
when it is made of a relitively soft material such as a lead
based alloy.
I used to fire 333grn cast bullets from an NEI mold from a
Super Redhawk on top of lots, and I mean LOTS, of
H110. It was a superbly accurete load for long range
shooting. The leading from this load was virtually nil even
though pressures must have been right at the upper end
of the .44 Mag limit. I've fired lighter bullets with big
charges of powder which have left lead on 50% of the
length of the barrel even though the pressures can't have
been any higher. I'm sure that sizing and alloy type have
more to do with it than does bullet base melting.
Regardles of what Rob Letham said, and I'm not doubting
his qualificatins one bit, I don't think this is a problem
with FMJ's. If it were we would have seen it in military
rifles, or at least with rifles using military ammo, before
now as they surely must work at greater pressures than
9x25mm Dillon. After all shotguns don't get plastic
deposits in their barrels from plastic wads or cartridge
hulls do they?
Another thing that occured. Modern primers use lead as
a major part of thier composition do they not? Perhaps
under certain circumstances lead from the primers is
being deposited in the barrel? Has anyone ever tested for
this?
Jonathan Laws.
--
I don't think comparing plastic to lead is really relevant,
I'm not sure what shotgun wads are made from but the plastic
is harder than lead and it will have a different melting
temperature, shotguns are smoothbored, wads may be
undersized, the velocity is much slower etc. etc.
I'm pretty sure it does happen in military rifles, to
be honest. It's only a small amount of lead, but it only
has to be a small amount. Because it happens inconsistently,
it can affect accuracy. There are plenty of SS109-type
bullets with the weight to the rear of the bullet like
an HPBT because they have a steel tip, but they don't
shoot as well as HPBT, even if you carefully select
the bullets to make sure of diameter and so forth.
Like I said I don't pretend to be an expert handloader
but certainly I know service rifle shooters in Canada
and elsewhere who have looked into that particular
aspect and HPBT beats FMJ every time. (Unfortunately
in Canada they have to use FMJ!)
Steve.
Cybershooters website: http://www.cybershooters.org
List admin: [EMAIL PROTECTED]
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