The 7mm STW Story
The search for a Bigger Seven opened the door for a family of magnum cartridges.
By Layne Simpson
All things--including chamber pressure, barrel length and
bullet weight--being equal, the ST family is usually about 200
fps faster than shorter cartridges of the same caliber. From
left to right: .257 STW, .257 Weatherby Magnum, 6.5mm
STW, .264 Winchester Magnum, 7mm STW, 7mm Remington
Magnum, .358 STA, .358 Norma Magnum.
One day back in 1979 when the 8mm Remington Magnum had been with us for a bit less than two years I
decided, just for the fun of it, to neck the new case up and down to various calibers. Realizing that the .338-
caliber version would do no more than duplicate the performance of an existing factory cartridge called the .
340 Weatherby Magnum, I quickly lost interest in it.
Nowadays the author hunts more with the 6.5mm STW than
with any other cartridge in the STW family and took this black
bear with a rifle in that chambering.
At the time, the 7mm version seemed to make the most sense for several reasons, one being
the fact that the popular 7mm Remington Magnum and 7mm Weatherby Magnum cartridges
were on the shortened Holland & Holland belted case, while our most popular rifles, the
Winchester Model 70, Remington Model 700 and Weatherby Mark V, were quite capable of
handling cartridges on the full-length case.
Since the cartridge I had in mind was on a Remington-designed case and since it was bound
to be faster than the short 7mms, I decided to call it the 7mm Remington Maximum.
At the time, powders of super-slow burn rates that would be required in
order to reach maximum velocities in the cartridge were quite scarce, and
for this reason the new wildcat remained nothing more than an idea for
several years.
My interest in the Bigger Seven project was renewed in 1986 when DuPont
finally got around to making available to the canister trade an old, slow-
burning propellant called IMR-7828. Up until that time it had been available
only to commercial ammunition manufacturers for use in the .264
Winchester Magnum and 7mm Remington Magnum.
During that same year Bob Hodgdon informed me that H5010, a military
surplus powder originally developed by DuPont for the .50 BMG cartridge,
was available from his company and a supply was headed my way. Not long
after that Hodgdon introduced another slow-burner called H1000, and soon
Rifles in 7mm
STW, from left to
thereafter Hercules (now known as Alliant) introduced Reloder 22. It was
right: Jarrett time to see how fast the big cartridge could run.
custom Model 700
(first rifle built in Kenny Jarrett put together the very first rifle in 7mm STW in 1987. Built on
7mm STW), a blueprinted Remington 700 action, it has a 25-inch Hart barrel with a
Webernick custom 1:10-inch twist and a McMillan fiberglass stock with that company's wood-
Model 700 (six grain finish. I have not kept an accurate record of how many rounds I have
pounds with fired in that rifle but am sure it is more than 1,000, and it still averages less
scope), than an inch at 100 yards.
Winchester M70
Sporting
Sharpshooter by When new, it averaged less than a half-inch with the Nosler 140-grain
USRAC Custom Ballistic Tip. The rifle still wears the same 2.5-10X Schmidt & Bender I
Shop. installed on it the day I got it. Its weight of 93?4 pounds makes it a bit
much for toting up a sheep or goat mountain, but it is ideal for sitting in
one spot and shooting away over yonder, which is mostly what I have used it for.
Shortly before Jarrett had completed the rifle I decided to change the name of the cartridge
to 7mm Shooting Times Westerner, or 7mm STW for short, and it stuck. My first article on
the new cartridge was published in Shooting Times in 1988, and to simply say that it took off
like a scalded dog among hunters across the country would be an understatement of the
facts.
At first, top management at Remington had no interest in the 7mm STW because as they saw
it, a factory-loaded version would spell doom for the 7mm Remington Magnum. Decision-
makers at Winchester Ammunition gave it an even colder shoulder because they feared that
other shooting publications would ignore it since its name contained the words "Shooting
Times." (Shooting Timesis now a sister InterMedia Outdoors publication of RifleShooter.--Ed.)
Kenny Jarrett built the very first rifle in 7mm STW in 1987,
and it still averages less than minute-of-angle accuracy.
The chaps at Remington eventually changed their minds, and why they did is one of my favorite parts of the
story. At the time, the 8mm Magnum was a dead duck; Remington had dropped it from the Model 700 rifle,
and ammunition sales had become practically nonexistent. Then suddenly, orders for thousands upon
thousands of rounds of 8mm Magnum unprimed brass began to pour in from distributors across the country.
As Remington's investigation revealed, all those cases were being sold to handloaders who owned rifles in
7mm STW.
A sampling of some excellent powders for the entire STW
family.
One of the reasons the 7mm STW became so successful so quickly was the fact that the
chamber of any rifle in 7mm Remington Magnum could be reamed out for it. One gunsmith
who charged $60 for a rechamber job (and who wisely ran advertisements in the issue of
Shooting Times in which my first article on the cartridge appeared) told me that within 12
months after my first article was published he had rechambered more than 600 rifles from
7mm Remington Magnum to 7mm STW. That was from only one among dozens of gunsmiths
across the country who were offering the same service.
Soon after Remington woke up to the fact that rifles in 7mm STW would sell, the wheels of
progress began to pick up more speed. Then in a ceremony held during the 1997 NRA annual
meetings, I was presented with the very first production rifle built in 7mm STW. I also
received the first box of 140-grain Core-Lokt ammunition to come off the production line.
That first load offered by
Remington was rated at 3,325 fps,
but, as many of us eventually
discovered, it exceeded 3,400 fps
in some rifles with 26-inch barrels.
Twelve months later Remington
had sold just over 600,000 rounds
of 7mm STW ammo, something I
used to take great joy in
mentioning to my friends at
Winchester who had turned down
the opportunity to beat their
competition to the punch. The 7mm STW is a descendent of the 8mm Remington
Magnum; RCBS made the first set of reloading dies.
7mm STW LOAD DATA
POWDER VELOCITY
DATA
BULLET (Type) (Grs.)
SOURCE
(Highest Velocity Loads Listed)
Hornady 100-gr. HP RL-22 83.6 3,800 Hornady
Barnes 100-gr. XBT RL-22 81.0 3,634 Barnes
Sierra 120-gr. SPT V-N 160 78.0 3,600 Sierra
Barnes 130-gr. XBT H4831 79.0 3,523 Barnes
Sierra 130-gr. MK RL-22 80.0 3,600 Sierra
Barnes 140-gr. XFB IMR-7828 80.0 3,473 Barnes
Nosler 140-gr. Part RL-22 82.0 3,382 Lyman
Nosler 140-gr. B-Tip RL-22 79.0 3,410 A-Square
Sierra 140-gr. SPT IMR-7828 79.0 3,400 Sierra
Barnes 150-gr. XBT H-1000 81.0 3,359 Barnes
Nosler 150-gr. B-Tip AA-8700 92.0 3,300 Nosler
Sierra 150-gr. SBT H870 91.0 3,350 Sierra
Barnes 160-gr. XFB H1000 80.0 3,287 Barnes
Nosler 160-gr. Partition IMR-7828 78.5 3,272 A-Square
Sierra 160-gr. SBT H870 88.4 3,250 Sierra
Barnes 160-gr. XLCFB N-MRP 79.0 3,384 Barnes
Nosler 175-gr. Partition AA-8700 89.0 3,047 Nosler
Sierra 175-gr. SBT H870 86.3 3,100 Sierra
Speer 175-gr. GS AA-8700 90.0 3,083 Lyman
Barnes 190-gr. Orig. IMR-7828 75.0 3,127 Barnes
Other companies besides Remington also played important roles in the success of the 7mm
STW. About four years before Remington adopted it, the custom shop of U.S. Repeating Arms
began to offer Winchester Model 70 rifles chambered for it. That made the Model 70 one of
very few factory rifles to ever be offered in a wildcat chambering. During a private meeting
with USRAC officials in 1993 I was told about a yet-to-be-announced custom variation of the
Model 70 and was asked to come up with a name for it.
The new rifle would be built for big-game hunting and it would wear a Schneider match-grade
barrel, so I casually mentioned that "Sporting Sharpshooter" would be an appropriate name
for the rifle. Shortly after that meeting took place I received the very first Model 70 Sporting
Sharpshooter built by USRAC. Even more surprising was "7mm STW" engraved on its barrel.
From that day on, the 7mm STW chambering was on the custom shop's list of options.
The next event that went a long way toward greasing the wheels of progress for the 7mm
STW was the 1994 introduction of custom-loaded ammunition by A-Square. During a factory
visit with Art Alphin, who owned the company at the time, I was asked which bullets should
be offered. Soon thereafter I received a batch of the ammo, and the 140-grain load clocked
an average of 3,437 fps when fired in my rifle. The 160-grain load averaged just under 3,200
fps.
So while Remington must be given a lion's share of credit for the success of the 7mm STW,
we must not overlook the fact that Winchester was chambering custom rifles for it and A-
Square was making the ammunition before Remington got around to adopting it. After
Remington made an honest cartridge out of the 7mm STW, Winchester, Weatherby, Sako,
Ruger, Tikka, Savage and possibly others also started offering rifles chambered for it.
Federal, Winchester and Speer (under the Nitrex label) started loading the ammo.
These days you are more likely see me in the field with the 6.5
STW, mainly because I have come to appreciate that bullet
diameter, but I still sometimes hunt with rifles in 7mm STW. In
addition to that first Jarrett rifle, the Model 700 Sendero given
to me by Remington and the Winchester Model 70 Sporting
Sharpshooter I mentioned earlier, my battery contains a
lightweight rifle built on the Model 700 action by Lex
Webernick that weighs six pounds with scope. It is actually one
of three matching Webernick rifles I own, the other two in .257
STW and 6.5 STW. I also have a Ruger No. 1 that was
rechambered from 7mm Remington Magnum. A good 160-grain bullet is hard to
beat for all-around use of the 7mm
STW on game ranging in size from
Right from the start the Nosler 140-grain Ballistic Tip proved to deer to elk.
be the most accurate bullet in my Jarrett rifle. I have taken
quite a few whitetail deer and pronghorn antelope at longish ranges with that bullet and have
even used it to bump off a caribou or two, but it is too soft to use on larger game, so for elk I
settled on tougher 160-grain bullets such as the Nosler Partition and Swift A-Frame.
As I grow older I tend to keep life more simple by using a good 160-grain bullet on
everything from mice to moose. The 160-grain Nosler AccuBond is also an excellent choice,
and a friend of mine is convinced that elk-bullet evolution ended with the Barnes X-Bullet of
that weight. When loaded to 3,200 fps and zeroed three inches high at 100 yards, either of
those bullets is just about dead on the money at 300 yards and less than a foot low at 400
yards, where it is still packing more than 2,000 ft-lbs of punch. A 140-grain bullet at about
3,400 fps shoots a bit flatter, but not by enough to really matter and it is nowhere near as
versatile.
As for factory ammo, I really like Remington's loading of the 140-grain Core-Lokt for deer and
Federal's Premium loading with the Nosler 160-grain AccuBond for all-around use on
everything from pronghorn and
deer to moose and elk.
Most who saw the sizes of their
groups shrink assumed that it was
due to the 7mm STW being a more
accurate cartridge than the 7mm
Remington, and while that may
very well be true I have my doubts.
Rather, I tend to believe that the
improvement in accuracy was most
often due to more concentric
chambers cut by the gunsmiths
who rechambered their rifles.
From the very beginning the Nosler 140-grain Ballistic Tip
was the most accurate bullet in the author's first 7mm STW
rifle.
6.5 STW LOAD DATA
POWDER
BULLET VELOCITY DATA SOURCE
(Type) (Grs.)
Sierra 85-gr. HP IMR-7828 85.0 4,016 L. Simpson
Nosler 100-gr.
H1000 88.0 3,863 L. Simpson
Partition
Speer 120-gr. SP H1000 83.0 3,511 L. Simpson
Nosler 125-gr.
AA-8700 91.0 3,515 L. Simpson
Partition
Swift 130-gr.
H50BMG 88.0 3,461 L. Simpson
Scirocco
Nosler 140-gr.
AA-8700 90.0 3,316 L. Simpson
Partition
.257 STW LOAD DATA
POWDER
BULLET VELOCITY DATA SOURCE
(Type) (Grs.)
Hornady 75-gr. HP RL-22 85.0 4,036 L. Simpson
Nosler 85-gr. B-Tip RL-22 83.0 3,914 L. Simpson
Nosler 100-gr.
H1000 86.0 3,709 L. Simpson
Partition
Nosler 115-gr. B-
AA-8700 92.0 3,546 L. Simpson
Tip
Sierra 117-gr. SBT AA-8700 89.0 3,507 L. Simpson
Nosler 120-gr.
H1000 82.0 3,466 L. Simpson
Partition
.358 STA LOAD DATA
POWDER
BULLET VELOCITY DATA SOURCE
(Type) (Grs.)
Barnes 180-gr. XFB RL-19 95.0 3,357 Barnes
Barnes 200-gr. XFB IMR-4831 90.0 3,217 Barnes
Nosler 225-gr.
H4350 87.0 3,182 Hodgdon
Partition
Barnes 225-gr. XFB IMR-4831 87.0 3,128 Barnes
Barnes 250-gr. XFB IMR-4831 86.0 2,995 Barnes
Nosler 250-gr.
H4350 89.0 2,981 L. Simpson
Partition
A-Square 275-gr. LL H4831 90.0 2,857 A-Square
NOTES: All powder charges are maximum and should be reduced
by 12 percent for starting loads. Cases for .257 STW and 6.5
STW formed by necking down Remington 7mm STW brass; .358
STA case formed by necking up 8mm Remington Magnum brass
and fire-forming with a reduced powder charge. All rifles had
26-inch barrels.
I still receive a good bit of mail from fans of the 7mm STW, but it has now lost a great deal of the
momentum it once enjoyed. Remington stopped promoting it soon after introducing its own 7mm Ultra
Mag, and not long after that the super-short magnums came along to steal even more of its thunder. Most
companies no longer chamber standard-production rifles for it, and few writers (including this one) even
bother to mention it anymore. But one thing is certain: The 7mm Shooting Times Westerner was a fun ride
while it lasted.
Remington's first 7mm STW factory ammo was loaded with
the 140-grain Core-Lokt bullet, and it often exceeded 3,400
fps in 26-inch barrels.
OTHER MEMBERS OF THE FAMILY
My first store-bought deer rifle was a Marlin 336 in .35 Remington, and I liked the caliber
so much that I eventually got around to hunting with rifles in .358 Winchester, .35
Whelen and .358 Norma Magnum. After using a rifle chambered for the latter cartridge on
a moose hunt in Sweden, I decided to neck up the 8mm Remington case to .358 caliber
and call it the .358 Shooting Times Alaskan. Kenny Jarrett built the first rifle in that
chambering for Bob Nosler and I got the second one, a switch-barrel Model 700 with its
other barrel in 7mm STW. A few months later I headed to Alaska, where I bumped off a
brown bear with the 250-grain Nosler Partition loaded to 3,000 fps.
I introduced the .358 STA to the world in 1992. Unlike the .257 STW and 6.5 STW, which
are nothing more than the 7mm STW case necked down with the original body taper and
shoulder angle retained, the .358 STA is the 8mm Remington Magnum case necked up and
fire-formed to minimum body taper and a 35-degree shoulder angle. Cases can also be
formed by necking down and fire-forming the .416 Remington Magnum case. When both
are loaded to maximum chamber pressure with 250-grain bullets, the .358 STA is about
200 fps faster than the .358 Norma Magnum. It pretty much duplicates the performance
of the 1920s-vintage .350 Griffin & Howe Magnum and the .350 Super Magnum, which
was introduced by Art Mashburn during the 1940s. All are on the full-length Holland &
Holland belted case.
At that point I had no intention of adding additional members to this particular wildcat
family, but letters from readers who requested cartridges of other calibers eventually
caused me to introduce the .257 STW in 1998. Lex Webernick built the rifle, and I first
used it and a handload with the Nosler 100-grain Ballistic Tip at 3,700 fps to take a nice
Coues deer down in Old Mexico.
About a year later I came up with the 6.5 STW, not because it had received a great
number of votes from readers but because I was quite interested in that particular bullet
diameter. The first rifle in that chambering was built by the Canadian firm Prairie Gun
Works, and the first game I took with it was a black bear on Vancouver Island. The
handload I used pushed along the Nosler 140-grain Partition at close to 3,200 fps.
When both are loaded to the same chamber pressures and fired in barrels of the same
length, I find the .257 STW to be about 200 fps faster with all bullet weights than the .
257 Weatherby Magnum. I also find the 6.5 STW to be about 200 fps faster than the .264
Winchester Magnum. Whether that much gain in bullet speed is worth the effort is for the
fellow who will be spending his own money for a new rifle to decide.
