From: firstname.lastname@example.org (Norman F. Johnson)
Subject: Re: [RELOADING] dacron fillers, gas checks, etc.
Date: 21 Apr 1994 21:54:55 -0400
# The use of Dacron filler as a wad was mentioned as an alternative
# to using gas checks. Can someone please provide some more infor-
# mation about this. How do you do it? Is there a quick and dirty
# way of cutting out little circular patches?
Wads (or various fillers) have been traditionally used with cast
bullets because the powders/charges generally recommended for use
with cast bullets are faster powders that, as a rule, take up
only a small part of the volume of the case capacity. The 47-70
is an excellent example of this with it's very large case that
was designed for black powder. Fillers have been used to protect
bullet bases also but their traditional use is as described.
Some (most) powder's ignition characteristics are sensitive to
powder position in the case, so wads and fillers have been used
to hold the powder in close proximity to the primer. This helps
keep ignition more consistent and theoretically produces more
accurate loads, if all other conditions are close to optimum. The
position of the powder is not as critical to accuracy as is the
consistency of it's position.
With a tubular or flake powder, if it is positioned near the
primer it will yield a higher velocity than if it is positioned
at the far end of the case. Powder leveled out in the case will
provide a velocity somewhere between these two extremes. Ball
powders are said to act in the reverse of the above but I have
not verified it because my approach to cast bullet loading is
somewhat different, but that is another story.
---------------BUT, BEWARE !!!----------------
The use of wads and fillers to hold the powder back against the
primer has resulted in the ringing of numerous chambers,
especially those of straight walled cases such as the 45-70.
Ringing is a radial enlargement of the chamber, usually occurring
at the base of the bullet in a cylindrical portion of the
chamber, i.e., in the body of the cylinder or in the neck of the
cylinder but, as far as I know, not in the transition of the two.
It can happen either suddenly (one shot) or gradually over a
series of shots.
This phenomena was first recognized (to my knowledge) in the
early seventies by serious cast bullet shooters. The word has
been long getting out but, although infrequent, the ringing has
ruined many a chamber. The NRA and the Cast Bullet Association
(which made the NRA aware of the problem) has for quite some time
recommended that no fillers or wads be used in any loads where
they are positioned against the powder so as to leave an air
space between the wad/filler and the bullet base.
The reason for ringing has not been established, but some hold
that the wad or filler is propelled forward and when it strikes
the base of the bullet, the bullet acts as a secondary projectile
and rings the chamber (in the same manner that a bulged barrel is
likely to occur if a bullet is lodged in the barrel and another
is fired behind it).
Three methods are commonly used to avoid the above discussed
problems of powder position sensitivity and chamber ringing.
1) Select powders that fill the case enough to avoid the
positioning problem so no filler is needed.
2) Position the powder by raising or lowering the rifle muzzle
before each shot - again no filler required.
3) Select a powder that has shown to be less position sensitive.
Two powders that have been used to accomplish 3), are 700X and
Wads that stay up against the bullet base do not pose the ringing
hazard described. Polyethylene (HDPE and LDPE) wads are commonly
used in place of gas checks to protect and seal bullet bases.
Wax wads of all sorts are used to do the same.
# by powder compression, or lack of. I've heard that having the
# case 100% full is optimal.
Theoretically 100% case fill is best but it does not usually work
quite that way. Only trial and error will tell for a given
gun/ammo combination. I find that selecting a powder that will
provide somewhere near 100% loading density is a reasonable way
to start, but am not surprised when another load that is consid-
erably less case filling is better.
# A few of my heavy loads for my .44 Magnum are slightly com-
# pressed. Here's my dilemma. For light target loads for
# the .44, is it better to use the .44 Magnum brass and have it
# roughly 50%-70% full of powder or should I trim it down to .44
# Special length and have a larger volume of the case full of powder?
Here again, only trial and error will tell, theory notwithstanding.