From: njohnson@nosc.mil (Norman F. Johnson)
Newsgroups: rec.guns
Subject: Re: Severe Powder fowling w/ Reloads
Date: 11 May 1995 22:37:18 -0400
Lines: 159

David,

# I have been have some trouble with my 357 Mag., 9mm Makarov, and
# 45ACP reloades.  I have notices especially in the 357 Mag. some severe
# powder fowling between and ontop of the riflings.  I have tried changing
# powders and primers with no luck.  Additionaly I am using hard lead
# bullets(Brinell 18) with each load.  Here is some load info:

Could you be confusing powder fouling with lead fouling?

Some stuff that you may be interested in:

Bore leading stems from numerous, but usually related causes.
The principle cause I have discussed here before but is one that
is little known or understood by the vast majority of reloaders.
It is gas cutting.  A bullet should not be more than .0005"
smaller in diameter than the throat (not the bore) of the gun.
This is true in rifle or pistol.  Smaller diameter (lead) bullets
will allow hot gases to rush by and erode the base and sides of
the bullet.  Some of the eroded metal plates onto the bore where
it is run over by the bullet.

The best cure to this source of bore leading is to fit the bullet
to that particular gun's throat.  Since only a few reloaders have
the ability to do this (throats on recently made revolvers being
typically several thousands oversize) another approach is to try
a softer alloy.  That is NOT a typo - a softer alloy will have
more tendency to obturate or "bump up" in the throat  and is
often successful in reducing leading, especially in non-magnum
loads.

In MAGNUM loads where bullets already fit the throat and leading
is still excessive, sometimes a harder alloy is the answer -
sometimes.  I find that most leading in this case is because of
the choice of powders.  It is my experience, speaking of magnum
loads, that one should use the slowest powder that will give the
desired performance to make for successful cast or swaged lead
bullet shooting.  My .44 magnums and .45 Colt boomer loads using
W-296 and H-110 give insignificant leading - and some of these are
much hotter than I would be willing to publish here.  My bullet
alloy is moderately soft, measuring 12-13 BHN and gas checks are
rarely used.

I have recently been trying pure lead bullets in my 45-70 loaded
ahead of a case full of MR-8700, moderately compressed.  To date
I have had no observable leading at 1300 fps in both the Marlin
and T/C Contender.  That is with pure lead, folks.  If the
buffalo hunters could do it, why shouldn't we?

It is possible the gun, not the lube or the powder is the
problem.  Back in the days when I was lube testing I discovered
that a properly finished barrel was far less sensitive to lube
type than one that was rough.  This awareness started when I
bought a Virginian Dragoon in .44 Magnum.  It had a burr around
the muzzle so severe that the .44 became a .41 when fired.  I
started to examine the bores very closely.  At the same time I
was shooting a .357 Magnum stainless Blackhawk - and tho it
withstood my dimensional scrutiny it would shoot a few rounds
with particularly good accuracy then lead like crazy!  For quite
a time I suspected that there was something inherent in the .357
cartridge that caused leading.  Not to worry.  When Veral Smith
came out with his theories and bore lapping compounds things
improved a lot!

I have learned to look for five things in particular when having
trouble with revolver accuracy that is apparently being ruined by
leading:

1. Bullets that are more than about .0005" (that is one half
thousand) under cylinder throat diameter - altho jacketed bullets
are USUALLY more forgiving of this sin.

2. A necked down area where the barrel of a revolver is screwed
into the frame.

3. Powder that is too fast for the application.

4. Cylinder throats that are smaller than the slugged (measured)
bore diameter.

5. Rough bores or burrs around the muzzle.

Usually numbers 1, 2 and/or 3 are the culprits.  Nos. 4 and 5
less often are the problem but are not insignificant.

Incidentally, I will repeat here an admonition that I have given
before.  When trying out a new gun, shoot it with all the stan-
dard stuff first.  You may find that those things that you have
come to regard as good or bad do not matter at all and the gun
will shoot to the very best of your capability without putting an
ounce of sweat or a dime of your savings into it.

If I had very carefully examined the bore of the Blackhawk that I
have discussed here before I first shot it, I could have
automatically assumed that it needed the Veral Smith treatment.
Its grooves are very smooth but the tops of the lands clearly
showed tool marks of the boring tool.  With properly fitted
bullets (the throats are .455" and the bore slugs at .449") it
shoots as well as I ever will.  An exception to my rough bore
theory? - absolutely!  But then guns and women often offer some
VERY nice surprises.

If any revolver leads when I am using my old standby home mixed
Alox and beeswax, I assume that it is the system, not the lube
that has failed.  So far I have always been able to find the
problem using the above approach.  I do not use gas checks any
longer to cure leading problems.  I do have a few loads that
shoot better with gas checks, but not because of observable
leading with the same loads sans gas checks.

If lead, rust, or powder residue are the problem:

Scrub the bore with Big 45 Frontier Gun Shop Gun Metal Cleaner.
It will zip that lead, rust and other crud out in a jiffy and
WILL NOT damage your bore.

The Big 45 stuff looks like a stainless steel Chor-Boy and is an
alloy that is harder than lead and softer than barrel steel.  Use
Lead-Away or the brass wire screen/rubber plug de-leader
that Hoppe's sells and then the Big 45 scrubber only to see
flecks of lead leave the bore when the Big 45 is used. This
despite the shiny, mirror finish of the bore after Lead-Away.

The Gun Metal Cleaner can also be used to scrub off external rust
without harming the bluing. Its great stuff and I have used it
for years after Skeeter Skelton recommended it in a column long
ago.

It can be had for $3.50 per package plus $.50 (total $4) from:

Big 45 Frontier Gun Shop
515 Cliff Avenue
Valley Springs, SD 57068
605-757-6248

Send check or money order.

Here is a testimonial after I recommended it to a list
subscriber.

# I took your advice, and ordered a bag of that Big 45 gun cleaner.
# Wow, that stuff is the greatest! I deleaded my model 29 in about
# 10 seconds, then cleaned  my Colt trooper .357. I brought the
# brush with the tuft of big 45 to our police range on Sunday,
# which runs a public shooting program. We got out one of their
# old departmental guns, really cruddy, and I gave it a shot. In
# about 15 seconds, it was spotless. They plan to order a couple
# of portions for their own use.   I really like the product, and
# have to get more for myself and to give my father. Thanks for
# the good tips in the firearms list.

God Bless!

Norm

From: njohnson@nosc.mil (Norman F. Johnson)
Newsgroups: rec.guns
Subject: Re: leading: prevention? removal?
Date: 25 Sep 1995 18:28:54 -0400

Clay,

# How can I prevent/minimize/just deal with lead deposits/  Two
# guns, 3" SW Model 36 .38 spl, cheap wadcutters, and Colt .22
# "pre-Woodsman" (thanks, Bob) ca. 1927 shooting Remington
# std vel ammo.  Last night I had to take a piece of insulation-
# hanger wire and gently poke at the lead deposits.

The below is an edited version of information that I have posted
before.  I have received the question so often lately that I am
posting the answer to the list.  Old timers may skip to next post.

In a revolver, the throats are the areas in each cylinder chamber
immediately ahead of the portion of the chamber where the brass
case rests and into which the bullet projects.  If the bullet is
sized so that it is a gentle force fit in the throat, all else
being equal, your accuracy potential will increase greatly.

Two factors come into play here to improve potential accuracy:

a) the bullet axis is forced to be more nearly coaxial with the
barrel axis than it would be if it were allowed to lay cocked at
an angle due to tolerances between cartridge and cylinder chamber
dimensions.

b) gas cutting, which will positively RUIN accuracy, is virtually
eliminated.

The above is true of cast (non-jacketed) bullets more so than
jacketed because cast bullets are more subject to gas cutting
but the importance of concentricity of the two axes should not be
under estimated.

Using an old C-H Swage-O-Matic bullet swaging press and
appropriately modified (opened) dies I am able to reshape and
resize most pistol bullets, including most of my cast bullet
rejects, to usable and usually very accurate projectiles.  If
one does not require that the increase in diameter exceed a
couple of thousands, and the bullet is not too hard, (no jacketed
bullets  here)  a  bullet  sizer with  the  appropriate  die  can
sometimes be use to "bump up" a given cast or swaged bullet to
proper size altho this does not provide the same control and
consistency as bullet swaging equipment.  Be careful tho, it's
easy to break the  sizer handle.

I have improved a Redhawk .44 Magnum from a "best" of 2" at 25
yds. to a constant .75" at the same distance by changing bullet
diameter alone.  Now THAT'S satisfying!!!

# How would I check/alter oversize throats?

You can check this by pushing a bullet through the throats of
your revolvers.  If they drop through freely, the bullets are
undersized for the throats.  IDEALLY, the throat should measure
one or two thousands larger than your MEASURED bore and the
bullet should be about half a thousandth less than the throats
(or the size of the smallest throat).  Throat diameters will vary
about half a thousandth on a typical cylinder.  I can say from
experience that if your guns are of recent manufacture they will
very likely have oversize throats.

The only way to correct this problem (from a practical non-
machinist standpoint) is to send the gun back.  I have done this
with three revolvers in recent years and new guns were sent to me
with ideal dimensional relationships.  It seems that the
companies will respond if one can relay the message that he
understands the problem.

There is, however, a work-around for over sized throats that does
not require gunsmithing.  Hollow based wadcutters (HBWC) were
designed so that the impact of the powder gases on the hollow of
the bullet will obturate the skirt to fill the throat and bore -
thus eliminating gas cutting.  This solves part of the problem,
which, for lead bullets, is the most crucial part.  It works for
milder loads only, because the high pressures of hot loads may
blow the skirt of the HBWC off, causing it to lodge in the bore
and become an obstruction.

Should the throats be undersized in relation to your bore (a
condition that is rarely encountered) they can be opened up by
a machinist or done at home using number 400 wet-or-dry sand
paper on a split dowel.  This must be done very carefully,
however, making sure that the dowel is not tipped in the throat
or an awful out-of-round mess will result.

God Bless!
	
Norm