of 3870, 3825, 3602, 3570, 3456,
3400, and 3305fps.
In case you’re wondering,
I believe that Weatherby's
continued loading of the short,
round-nosed 117gn bullet is
retained in consideration of
any old 1:12" twist rifles made
in this calibre before 1973 that
may still be in use.
Long ago, Ray and I both
realised the cartridge delivers
its best performance on game
with heavy bullets weighing
from 110 to 120 grains. It’s too
hard on barrels to use on
varmints, so no advantage to
using bullets lighter than 100
grains. Energy rating for the
.257 Wby with a 100gn bullet
leaving the muzzle at 3620 fps
is 1388 ft/lbs at 400yds, but a
nicely pointed 115 grainer
starting out 200 foot seconds
slower reaches the 400yd mark
with and 2547 fps and 1656 ft/
lb remaining. When both loads
are zeroed for 300yds, the drop
at that distance is practically
the same 7.7 and 7.9 inches.
The only competition the
.257 Weatherby has comes from
the .25-06 Remington, its
closest rival in terms of bullet
speed and downrange energy.
“Big Green” loads it with 100,
115 and 120gn bullets at
speeds of 3230, 3000 and
2990fps respectively. But while
it is an excellent cartridge, andbenefit shooters and hunters.
The bolt has no external
guide ribs or lugs to align and
retain it within the receiver.
This function is accomplished
by the bolt stop stud in the
bottom of the receiver, which
rides in a longitudinal groove
in the bolt body. The bolt
handle is sharply raked back
and has a round smooth knob.
The magazine is a top-
loaded, and holds 3 rounds in
a staggered column. A pressed
steel cartridge box fits under
the receiver and tabs on the
upper front section are bent in
to form cartridge guide lips.
The one-piece magazine framewith hinged floorplate is alloy
with a release button housed
in the trigger guard. The
follower is some kind of
composite material.
The Mark V trigger is an
override type, adjustable for
weight of pull and sear
engagement. It has a rearward
pivoted sear which engages
the cocking piece squarely and
receives upward tension from
a small coil spring. The trigger
of my test rifle breaks
consistently at a crisp 1.36kgs.
The two-position, direct
acting safety catch mounted
on the side of the bolt sleeve,
cams the cocking piece back
free of the sear and locks the
bolt handle down, a system
I am very much in favour of.
The slim 650mm stainless
barrel is blackened to reduce
glare, has a target crown and
is fluted to reduce weight and
hasten cooling. The rifling has
a twist of 1:10 inches and the
chamber has .378 inch of
freebore. This extra length in
the throat gives the bullet a
running start before it engages
the rifling and reduces
pressure somewhat.
The Wby Mark V’s magazine
box has been shortened
slightly but is still long enough
to handle cartridges with an
overall length of at least 3.54"
(90mm). This enableshandloaders to seat long,
heavy bullets out far enough to
reduce the amount of jump,
but experience has shown that
this approach doesn't always
improve accuracy. In fact, I've
never found that having
bullets make a long jump to
reach the rifling had any
detrimental effect upon
accuracy. Most Weatherby
rifles I've owned have all
produced excellent accuracy.
The same goes for my friend
Ray Smith who has always
owned a rifle in .257 Wby for
as long as I've known him- over 50 years. In that time
he's tried many different
powders in a number of
.257Wby rifles and barrels
and has reached the same
conclusion that I have; when
it comes to gaining top
performance from the
cartridge, Alliant Reloder 22
and Reloader 25 cannot be
bettered. Only with these two
powders have we been able to
consistently equal the
velocity of Weatherby’s
factory ammunition at safe
working pressure.
Weatherby ammo is made by
Norma in Sweden and seven
different bullet weights are
listed for the .257 Wby
Magnum – 80gn, 87gn, 100gn,
110gn, 115gn, 117gn and
120gn. At respective velocities
56 | SPORTING SHOOTER _ APRIL 20154
The Mark V Ultra Lightweight’s
stock has a molded-in aluminum
chassis which provides a very even
and uniform bedding platform.
5
Bolt is fluted and has three
gas holes in right side to vent
escaping gas in the event of a
blown primer. Mount bases are
Talley. Note red dot cocking
indicator behind safety button.
6
The large diameter Mark V bolt
is equipped with nine locking
lugs in three banks of three,
reinforcing its reputation for being
“the world’s strongest action.”
7
Mark V receiver is massively
proportioned, but thicker lef t rail
provides most of the action’s rigidit y.
ON THIS SPREAD
TEST
REPORT4
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