From: andrew, [EMAIL PROTECTED]
Let me say it again! The base of a bullet doesn't and
cannot be melted by either the primer or powder, there
is not enough heat and not enough time. To prove this
point some years ago I took what was left of a plain
base cast bullet that I had fired in my .375 H&H to
our metallurgy lab for examination. The bullet had
been pushed out with 72 grains of N140 at around 2700
fps, if anything was going to melt the base this would
be it! Myself and the technician examined the base
through both optical and electron microscopes and guess
what? No melting. So the bullet base is not melted
either in reality or theory. The only part pressure can
play is in causing plastic flow, which as I pointed out
before is not melting. Before telling me that my "baked
alaska" analogy is wrong go talk to a thermo engineer,
the key phrase is "latent heat".
A key factor in the successful use of cast bullets is
to make sure the bullet fits the barrel, the bullet
must be groove dia. or larger. The lead fouling problems
with 9 m.m. pistols is largely down to this. The nominal
size of 9 m.m. barrels is listed at .354 inch but I
examined many barrels of various makes and age and the
closest one was .356 inch, on a 1944 p.38! A friend had
a cz 75 that wouldn't shoot cast at all until I convinced
him to use .359 dia. bullets, instant success! The barrel
was .3585. What's the betting that those .357 sig barrels
are over size? The same thing is the root of reports about
Marlin microgroove barrels not being able to handle cast
bullets. The barrels I've measure were all over nominal
size (.458), my .45-70 is .4596 obviously .458 dia.
bullets are a waste of time but I use .460 dia.
plain base cast bullets which give moa accuracy at 1800
fps when I do my part.
You will get some lead deposited in the bore, just as
you get jacket metal deposited, but it should remain
constant and have no effect on accuracy. The only
firearm I expose to jacketed bullet bullets is my
.223, on about four occasions a year and that is about
the only time the barrel gets cleaned; once before and
once after. I am currently putting around 150 rounds
of cast bullet loaded ammo through my .223 per week
and get consistent sub moa accuracy at over 2400 fps.
Another factor to consider is that I have been casting
and shooting cast bullets for over two decades and so
far the main problem to using them is having to put
up with people telling me that what I am doing cannot
be done. My favourite was at Bisley (where else?)
shooting my MP 43 assault rifle at 600 yards. We were
joined by someone who took it upon himself to tell
anyone who would listen that rifles like mine should be
banned and had no place on a range as they were not
accurate anyway! The fact that my target was going down
with every shot with a good number in the middle did
not bother him at all until someone blew his mind by
telling him I was using bullets cast from car wheel
weights.
--
I don't think there is any point comparing cast bullets
to jacketed bullets, that is a whole different ballgame.
Perhaps it is just the pressure pushing the base of
the bullet out of shape, I don't know, and it doesn't
really matter, the effect (i.e. crap accuracy) is the
same.
.357 SIG is not .357, it is just a 9mm bullet in a
necked down .40 S&W case, they use the same tooling
for doing the rifling on the barrels for the 9mm and
.357 SIG. In fact for the P226 barrels used in the
Sport models with the oversize (9mm) barrels, it
is identical to the .357 barrel except that the chamber
has been cut differently. (On the subject of the
.357 SIG, has anyone got a Glock 32? Any good?)
I had one of those CZ75s, you could push a 9mm bullet
through the barrel with a pencil. After the wall fell
they invested in new tooling as the newer ones are much
better. Gary Clark miked the barrel at just under .359"
on mine!
Steve.
Cybershooters website: http://www.cybershooters.org
List admin: [EMAIL PROTECTED]
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