The 300 Whisper certainly caused a sensation
in the shooting world when it first came out - basically because it broke every
rule in the book. Those very same rules are still very much in force today and
are probably even more entrenched in most shooter’s minds. What are those
rules? Simply “smaller diameter bullets are better than larger diameter bullets”
and “faster loads are better than slower loads”. Well here was a cartridge that
was designed to do the exact opposite i.e. take a 221 Fireball case, expand the
neck to 30 caliber and shoot a 220 grain Sierra bullet out of it at subsonic
velocities (less than 1100 fps) in a fast (1: 8) twist barrel. It was really a
pretty radical idea and still is.
The 300 Whisper was designed by the
indomitable and innovative J.D. Jones, an ex-IHMSA match director and owner of
SSK Industries, home of the “Hand Cannon”. J.D. saw that a long, heavy, slow
moving bullet was perfect for both specialized military applications and as a
general sporting cartridge. Why? Because those long jumbo bullets become very,
very efficient in the subsonic regime. So what does that mean? To find out,
let’s look at some some comparative figures.
Let’s take the 7 TCU, which is about as
average a silhouette cartridge as there is. We’ll assume that we’re going to
launch a 140 grain Sierra flat base bullet out of a 14” TC. We’ll be using a
load of 28.4 grains of Winchester’s 748 powder. Velocity is a very respectable
1900 fps.
On the other hand, our 300 Whisper is going
to be using a 220 grain 30 caliber Sierra bullet moving along at a very
leisurely 1050 fps - almost half the speed of the 140 grain bullet. Let’s see
what happens at 200 meters.
When the 7 TCU’s 140 grain bullet hits the
ram, it’ll be going 1349 fps. In other words, it’ll have lost a whopping 551
fps, or nearly 29% of its original velocity. In a very gentle 5 mile an hour
side wind, it will have also drifted over nearly 6 inches. Additionally, recoil
will be 15.3 foot pounds, which is considered moderate. Striking momentum on the
ram will be .83 pound seconds - safely adequate to push the ram over.
The 300 Whisper will be a very different
story. When its 220 gr bullet hits the ram, it’ll still be going 983 fps.
Amazingly, it will have only lost a miserly 67 fps over the 200 meter
course! Compare that to the 7 TCU loosing 551 fps at the same distance. Well,
you might say, there’s bound to be a lot more wind drift because the bullet is
moving so slow. Wrong. That’s not how it works. Wind drift will be only 3.8
inches or 36% less than the 7mm bullet. How about recoil? That big 220 has got
to produce a lot more recoil than the 140, right? Wrong again. Recoil comes out
to only 6.6 foot pounds - 56% less than the faster, but smaller 140 gr
bullet. Momentum knockdown for the Whisper will be .96 pound seconds or 13.5%
more push on the target. So here we have a case where you have less velocity
loss, Oh, by the way, the Whisper can do all that while delivering a half MOA in
accuracy at 200 meters.
So how does the Whisper do all these great
things? It all comes down to drag and ballistic coefficient. First drag. When
any bullet is traveling at supersonic velocities, it’s pushing a thick wall of
highly compressed air in front of it. When it’s traveling at sub-sonic
velocities, it’s not. It’s that simple. The faster the bullet is traveling, the
more drag it has to overcome. Since the Whisper is moving relatively slowly,
there’s far, far less drag. The Whisper trades speed and energy for weight and
momentum, which is far more important when kicking the ram’s face into the dirt.
Now let’s talk about ballistic coefficient,
which is a measure of the bullet’s ability to slip through the air. Our 140 gr.
bullet has a coefficient of .248. On the other hand, the long heavy 220 grain
bullet has a coefficient of .331. Longer is better when it comes to slicing
through the air. Bottom line: a long bullet at subsonic velocities is much more
efficient than a shorter bullet at supersonic velocities.
I was rooting around in the closet in my
gun room not too long ago and ran across a 14” TC barrel chambered in (you
guessed it) 300 Whisper. This was a standard barrel that I got not long after
Thompson Center introduced the cartridge into its lineup. I thought to myself
“You know, you haven't used this thing in so long, you ought to be ashamed of
yourself.” It was true. That barrel has languished in the closet for for years
and years and I really didn’t have an excuse for not using it. Needless to say,
I decided to take it out and have some fun.
Unfortunately, TC doesn’t offer the 300
Whisper any more except through its custom shop - Fox Ridge Outfitters. Fox
Ridge makes its barrels one at a time by taking standard grade TC barrels and
providing them with a custom reamed chamber and crown. The individual attention
these barrels get produce a superior shooting product. The Fox Ridge barrels
also receive extra attention and time on the polishing wheel which results in a
much glossier finish.
When TC brought out the Whisper many years
ago, they decided not to market the Whisper’s unique ability to deliver very
heavy bullets at long range with unusual accuracy. Instead, they promoted the
300 Whisper as a standard 50 -100 yard deer hunting cartridge using 125 to 150
grain bullets at supersonic velocities. Consequently, TC barrels use a 1:10
twist, versus J.D.’s barrels, which use a 1:8 twist.
With all the conflicting information floating around in
the gun press about subsonic and supersonic velocities, it was only
natural that the silhouette shooters of the time would naturally become
confused about which was the best way to use the Whisper. Eventually,
three camps evolved into being. There were the subsonic advocates, the
supersonic advocates, and those that combined the two concepts by driving
extra heavy bullets as fast as they could, often well beyond the limits of
reason. I still vividly remember one fellow who wondered why primers were
falling out his cases after only about three reloads. Seems he was pushing
180 grain bulk bullets out of his ten inch Contender at well over 1800
fps. He also insisted that recoil with his loads was very mild and
gentle. However if you look at the numbers, recoil was actually in the
heavy 44 Mag range. Eventually, the conventional or traditional supersonic
school of thought ended up dominating the Whisper’s use in silhouette
shooting.
Reloading the 300 isn’t difficult. Dies are
available from a variety of sources. Mine were made by RCBS. The unique thing
about 300 Whisper dies is that they contain a special expander die. Remember
we’re expanding the neck of the 221 Fireball case from .224 all the way up to
.308. That’s quite a jump, even with a special die to do it. Consequently, you
have to make sure the inside of the case is well lubricated and chamfered when
doing so. If they aren't, you’re going to have split necks. After the necks have
been expanded, just run the case into the full length sizer die and fire form
afterwards. After your cases have been fire formed, back off the sizing die
about a quarter turn to neck size only.
The Whisper was a very flexible case to
reload and was amenable to providing good results in my standard TC barrel with
a wide variety of powders. They ranged in burning rate all the way from Accurate
Arms #5, to Hodgdon’s H4198. H110, V120, and AA #5 gave exceptional results.
Bullet weights also ranged from 150 to 200 grains. Primers were restricted to
Remington 7 1/2’s basically for the sake of simplicity.
I used two types of cases for my little
evaluation i.e. standard Remington 221 Fireball’s reformed in my RCBS dies, and
ready made cases available from SSK Industries. The SSK cases are made from
mixed, once fired military 223 cases. The cases are cleaned, cut back, reformed,
primer crimps removed, and then polished to a high luster. All you need to do is
fire form. Some purists might be put off by the fact that these are mixed
military cases. However I found that getting 1” groups with them was pretty
routine. Being basically a lazy person, I like the idea of being able to buy
custom cases ready made. Additionally, I also like the fact that the 223 based
cases are stronger and so should last longer. However, if you choose to load
your ammo on the ragged edge of sanity, use the Remington cases to avoid any
surprises that may result from varying case wall thicknesses.
As many people have known for some time,
the 300 Whisper is a natural for cast bullets. If the idea of 200 grain subsonic
bullets appeals to you, but the cost of jacketed bullets makes you hesitate,
cast bullets are a logical answer. I found the RCBS 200 gr. bore riding
silhouette bullet to be a very good performer. Indeed, it provided some of THE
very best groups in the evaluation. Leadhead’s 200 grain bullet would also be a
logical choice, although unfortunately I discovered I didn’t have any to use for
this particular evaluation. The SAECO and RCBS 165’s would also be a good choice
if you wanted something in the middle range of performance.
A quick additional word on barrel twist.
If you want to shoot 200 or 200 grain plus bullets at subsonic velocities, a 1:8 twist barrel is mandatory. The Fox Ridge barrels as mentioned before are 1:10 twist. In that case, you’ll want to get your barrel from SSK, the Whisper
specialists, or from one of the other custom Contender barrel makers. The 1:8
will also give exceptional accuracy with the lighter bullets as well. It’s a
very flexible twist, adaptable to all 30 caliber bullets.
If you don’t mind giving up the advantages
of subsonic bullets and want to shoot the 200 grainers faster than sound, you
can use the Fox Ridge barrels and get very good accuracy. However, you won’t
give good accuracy with 220 grain bullets in a TC no matter how fast you shoot
them. The 1:10 works fine with the lighter bullets.
My evaluation gun was a standard 14” TC
equipped with a wide, flat custom forend that I got from West Coast master TC
smith, Jim Henry. The wide configuration is especially helpful to stabilize the
gun when shooting off sand bags. The gun was also equipped with Burris’s
outstanding 4 X 12 pistol scope mounted in Weaver’s very classy Grand Slam scope
rings. All chronograph results were recorded on my Oehler 35P sited 10 feet from
the bench.
In summary, I can say that the Whisper is
an extremely flexible cartridge to load for and is a delight to shoot. Getting
sub inch groups with either heavy bullets or light bullets isn’t really a
problem. With the right loads, this inexpensive run of the mill Contender can
can match the very expensive custom bolt guns shot for shot. It makes me wonder
how much better the Whisper would do if one invested a little more money in a
SSK barrel which uses Shilen match barrel stock.
The 300 Whisper is still an innovative,
cutting edge cartridge that won’t beat you up during the course of a match and
yet deliver all the accuracy and knockdown that you need to slap steel on both
the full sized or half sized animals - and yes, when using something like Nosler’s 125 or 150 grain Ballistic Tips, you can hunt deer with it too.