24 | SPORTING SHOOTER _ APRIL 2015
basis of interior ballistics study
of a cartridge. From this figure
you are able to know instantly
what your cartridge will do
in relation to others. Can you
tell me how accurate this
comparison would be for
calculating load data for a
wildcat based on the necked
down .284 case? I want to build
this wildcat to equal the .25-06
by having my .308 rebarreled.
I’d like to use a 120gn bullet
for deer.
- Ben Moody
A
True, measuring the
amount of water a .25-284
case will hold filled with water
to the brim will allow you to
compare it with the .25-06, but
there’s a bit more to it than that.
For instance, the .25-06 case
normally holds only a grain or
so more than the .25-284 - say
67.6gn against 66.6gn. This
seems to indicate that the
.25-06 could be loaded to
slightly higher velocity with
the same chamber pressure as
the .25-284, but things are not
that clean cut, since brass
varies in capacity in different
makes and lots. A certain
brand of .25-06 case may hold
2 grains of water more than
another and have even more
capacity than the .25-284,
another brand may hold exactly
the same, while yet another
may hold less than what is
regarded as average. This isn’t
going to be of much help when
you want to work up a load for
either cartridge, because case
capacity is not quite the same
as loading capacity which is
the premise for the
mathematics of interior
ballistics. To ascertain loading
capacity you simply use a
hacksaw to cut a shallow
groove in the shank of the
particular bullet you are going
to use, insert it in the sized case
neck and seat it to the depth
that you’ve previously
determined will just miss
contacting the lands. Water in
this portion of the neck will be
squeezed out through the
groove. Dry the outside of the
case and weigh again; this
figure is your case loading
capacity. Since different
lengths of bullets will be seated
to different depths, this method
will give you the loading
capacity of the case which will
probably be 5 grains less than
case capacity. Once you have
this figure, let your computer
programme do the job for you- to calculate the correct
powder charge at a given
pressure and known velocity.
Or more simply, reduce the
.25-06 load with the same
bullet weight by 10-percent and
work up one grain at a time. My
computer calculated the best
powder to be AR2213sc, the
starting charge with the 120gn
Hornady bullet was 50gn with
a possible maximum of 53gn
for a velocity of 3030fps. The
very deep seating required for
the heavier bullets in the
.25-284 cuts its powder
capacity even more. Personally,
I’d stick with the 100gn Barnes
TSX which can be driven at
3280fps using 56gn of
AR2213sc. Warning: this
cartridge is touchy to work
with at high pressures and it is
wise to always carefully check
pressure signs and back off
a bit when case heads expand
even as much as .001".
He’s Smart To Be Wary
of The .223 WSSMQ
I’ve been offered what
looks to be the bargain of a
lifetime. If it was in any other
calibre, I’d have jumped at it. It
is a Model 70 Winchester
Featherweight in .223 WSSM (I
call it WSFU – short, fat and
ugly). It comes with bases, rings,
die set, 40 factory rounds and
20 fired cases. I’m a sucker for a
bargain, but the Hornady
Manual says that when they
developed loads for the
cartridge, their test rifle had the
throat badly eroded after about
350 rounds. Consulting with
people on the internet, and we
all know that the internet has
high standards to preventabout guns posted on there
than anywhere else. When it
first appeared, I tested a Model
70 in .223WSSM. It was
accurate enough and gave no
problems with feeding, but
judging by the capacity of the
case, I knew that barrel life
would be short. Later I had
a Ruger Number One in .223
Rem. rechambered to .223
WSSM and it worked just fine,
but the rifle was just too heavy
and clumsy, so I sold it to a true
believer. I shot a number of pigs
and goats with the Ruger and it
killed well with the 64gn
Winchester bullet designed for
it. My best loads were: 55gn
Nosler Soid Base and 39gn of
AR2208 for 3650fps; 60gn
Hornady SP and 47gn Re-22 for
3520fps; and 64gn Winchester
and 47gn Re-22 for 3430fps. My
opinion (not for the internet) is
that the WSSM carridges were a
disaster which is obvious from
the way they died at birth. I'd
leave some other sucker buy
that gun if I were you and breath
a sigh of relief at missing out on
owning such a dreadful turkey.Rechamber .22-250
to .22-284Q
What’s your opinion about
having my .22-250 Howa
rechambered to .22-284? Will
it be worthwhile from the
standpoint of obtaining the
highest possible velocity from
a .22 hotshot for long range
varmint sniping? I would like
some information on dies,
loads bullets etc.- Des Stapleton
Barrel life is
likely to be
about 1000
r ou nd s.”
ASK THE
GUN EDITORpeople posting things they
know nothing about, the
consensus is that .223 WSSM
rifles have problems with
feeding, accuracy, barrel life
and so on. The barrel is very
light and thin and I can
imagine it would glow like a
light sabre from Star Wars after
a few rounds. If it were any
other calibre, say .223 Rem.,
I would grab it so fast – except it
would have already been sold.
Would this calibre handle goats
with the 60gn Nosler Partition?
What loads and bullets would
you suggest. I have noticed that
in the Nosler and Hornady
manuals standard ADI powders
do quite well. The gun is pretty,
it’s light and almost new. What
is your advice?- Richard Meyer
A
I don’t think that a Model
70 Winchester in .223
WSSM is much of a bargain at
any price. Barrel life is likely to
be about 1,000 rounds (if you
are lucky) and the rifle can only
be rebarreled for one of the
WSSM cartridges - .223, .243 or
.257. The .257 is the best of a
bad lot, and equals the ballistics
of the .25-06. Your faith in the
stuff you read on the internet is
touching, there’s more rubbish