From: "Alex Hamilton", [EMAIL PROTECTED]
Their pistol powder, N310, seems to develop a particularly
'hot' flame front in that I used to experience really
severe leading problems in the chamber throats of my S&W
686 - but not in the barrel - even with the recommended
target load of 2.8 grains of N310 behind a 148 grain GECO
lead hollow based wadcutter bullet in a 38 Special case
with Winchester or Federal primers. That load produced a
muzzle velocity of about 770 ft/sec - checked over my
PACT chronograph - and should not have resulted in such
leading. The chamber throat dimensions of my pistol were
not excessively large either. (I found that 2.7 grains of
Hercules - now Alliant - 'Bullseye' powder behind the same
bullet in the same cases with the same primers produced far
less leading but was a much dirtier 'burn' - leaving smoky
deposits all over the gun
_________________________________________
I have loaded many thousands of rounds in 9mm Para using
Vihtavuori N310 and fired them in a 1915 Luger without
any leading whatsoever and had lots of leading in a Colt
Python revolver with any powder including N310.
It is a great pity that you no longer have your 686 to
test my theory, but it is more than likely that the
leading in the throat had been caused by gas cutting. Did
you use bullets sized to the exact diameter of the cylinder
exit holes? This is crucial in revolvers and the bore
size is irrelevant. You would have made the leading
worse by using 38Special cases as that would have left you
with an annular gap of .125" in front of the case necks.
Another common problem I found was that the commercially
swaged hollow base wadcutters were too hard and did not
readily set up on firing, especially not at 770 ft/sec™,
which caused gas cutting unless the loads were stoked
up. The leading stopped in my Python with 3.6grs of
Bullseye, but the "bang" and recoil made precision
shooting more difficult and I was starting to get
occasional split skirts.
However, with home swaged hollow base wadcutters, swaged
from pure lead wire, I did not get any leading with 2.6
grs of N310, because they were soft and obturated the
bore perfectly. I used to clean the cylinder and
barrel on the average every 500 rounds and find no
leading anywhere.
This is now theoretical, but if you are getting any
leading at all something is wrong somewhere and the
accuracy will deteriorate fairly rapidly. This is even
more critical in full bore rifles. Firing bullets
sized only .001" smaller that the throat means that
one is dead lucky to hit the target at all at 200 yds.
Alex
--
Another point I'd like to point out here is that
powder can vary from lot to lot. Sometimes
it can even be a completely different powder
altogether, I seem to recall Accurate Arms did
this, they completely changed the powder but
called it the same name!
I had some American Eagle .22 that was awesome,
but the current batch I have seems to have been
loaded with curry powder or something similar.
Anyway, Richard does have his 686 so maybe he
can try out your suggestions!
Steve.
Cybershooters website: http://www.cybershooters.org
List admin: [EMAIL PROTECTED]
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