A_S_S_2015_04

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How the .25s stack Up. L To R: .250
Savage,.25 Souper, .257 Roberts,
.257 Ackley Imp., .25-284, .25 WSSM,
.25-06, .25-06 Ackley Imp., .25 WSM
and .257 Wby Magnum.

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Mark V Ultra Lightweight has a
drop-out floorplate with the release
catch inside the trigger guard. Note
Weatherby logo in gold on guard bow.

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The .257 Weatherby is
unparalleled as a long range
cartridge for all medium game up to
the size of red stag.

I asked Nioa Trading if they

could send me a new US-

manufactured rifle in .257 Wby

Magnum. The model they sent

was designated as the Ultra

Lightweight but it didn't live

up to its name. Despite having

alloy bottom metal and a slim

fluted barrel, it weighed 3.4kg

naked, or 340 grams more than

its advertised weight. Made

field-ready by attaching a

Leupold XIII 2.5-8x40 in Talley

mounts, the heft was increased

somewhat. Not enough to give

a foot hunter fallen arches,

but its bulk combined with

an overall length of 1175mm

makes it better qualified as

a plains rifle rather than

a mountain rifle.

There can be no mistaking

the rifle's origin. The contours

of the tan-coloured synthetic

stock with thin black

spiderwebbing is instantly

recognisable. The trademark

Weatherby handle has a high

Monte-Carlo comb with

rollover cheekpiece which

lifts the shooter's head into a

natural position for a scope.

The comb slopes up toward

the rear so that on recoil, it

slides out from under the

shooter's face. Many shooter's

prefer this design, while

others, favour the straight-

comb classic stock, which

from time to time Weatherby

has offered on select models.

Other features include the

angle-cut forend tip, sharply

curved pistol grip and 20mm

thick Pachmayr Decelerator

recoil pad. The specially

lightened synthetic stock is

made of aramid, graphite

undirectional fibres and

fiberglass. Molded into it is a

CNC-machined chassis of

aircraft-grade 6061 T-6

aluminium that stiffens the

receiver area and forms a

stable bedding platform.

The receiver and bolt are

forged of S.A.E 4140 chrome

moly steel, which has been

heat treated to give it a tensile

strength approaching 200,000

CUP. The Mark V is an

exceptionally strong turnbolt

action that’s massively

proportioned and constructed.

The bolt has nine locking lugs

in a three-row array set about

120 degrees apart. This

arrangement results in a low 56

degree bolt lift, compared with

the 90-degree rotation

necessary too unlock a Mauser-

type action. The locking lugs

have the same diameter as the

bolt body, thus, the Mark V

needs no lug raceways milled

in the receiver sidewalls.

Except for the nine inwardly

protruding lug seats in the

receiver ring, the receiver

interior is a simple cylindrical

tube and shallow multiple

lugs allow extra-thick

sidewalls. This not only

increases the strength of the

breech lockup, but also aids the

smoothness of bolt operation.

The Mark V’s locking system

is super-strong, but the

receiver's rigidity is reduced by

having a magnum- sized

magazine and loading cutouts

which are weak points since

they leave little metal in the

right rail and it is left to the

heavy left rail to provide most

of the action's rigidity. The

integral recoil lug is large, at

28mm wide, a height of 10mm

and is almost 10mm thick.

The bolt face is deeply

counterbored to shroud the

cartridge head, and the barrel

breech is in turn counterbored

to accept the bolt head. Hence

Weatherby’s breeching system

provides near maximum

support to the cartridge case

head by surrounding it with

three rings of steel in a similar

fashion to the Remington 700.

The plunger-type ejector is

powered by a strong spring and

is located at 3 o’clock directly

opposite the extractor which is

a close fit for a cut-out in the

counterbore rim. The flared

claw grips about one-sixth of the

cartridge rim, and a pivot and

coil spring arrangement

provides resiliency for push-feed

engagement during bolt closure.

Three gas ports 3mm in

diameter on the right side of the

bolt body allow escaping gases

to be vented in the event of

a punctured primer. Additional

protection for the shooter is

Mark V Ultra Lightweight.257 We atherby Magnum

54 | SPORTING SHOOTER _ APRIL 2015

ON THIS SPREAD

The .257 Weatherby is the largest commercial .25 cartridge, with

ultra-high velocity, super-flat trajectory more downrange punch than

any other .25-calibre round.

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TEST

REPORT BY NICK HARVEY