Weatherby Japanese Semi-Auto Shotgun |
FIREARMS INFORMATION
This will cover the Centurion, Centurion II, and 82 semi-autos
made from 1972 thru 1989
These semi-auto shotguns
are
discontinued and have been for years, with most parts being obsolete.
We will deal primarily with the semi-autos here, however the pumps may be
mentioned, as they a are a parallel
gun to the semi-autos as they utilized many of the same parts. All
these guns have the model designation engraved on the LH side of the receiver.
You
may want to take a look at the exploded views page
CLICK
HERE as much of the nomenclature used by Weatherby on these
guns do not match what we normal associate with US made forearms.
They call the recoil spring links, carrier extensions, and the breech bolt
carrier, simply a carrier.
The one part that seems to give the most trouble, is the slide assembly
on the semi-autos, this will break, and
welding
usually is not successful. The main reason
I believe, is that there was no provision for a recoil buffer in this
firearm. Also we have found that possibly on a batch of slide arms
that the factory may have manufactured them by cutting the material cross grain
instead of with the grain of steel, resulting in a weaker part.
These
firearms were made by 2 different manufacturers, with even a phase-in / phase-out
overlap. We have not been able to find any differences in parts between
the 2, as the firearms appear identical except the serial number prefix.
Weatherby Centurion & Centurion II |
|
Centurion ;
These
guns used a aluminum receiver, ventilated rib barrel, had a nicely
finished checkered walnut stock that had a white line spacer between the
rosewood grip cap. They used a non compensating gas system which
used only the recoil spring in the buttstock to absorb recoil without a stop
buffer in the rear receiver. The locking system and operating handle was
quite similar to the Remington 1100. Fixed chokes in the
barrels. The early versions used a single cast carrier extension
that was slotted down the center allowing the hammer to extend up thru the
extension when firing.
The
wood forearm front was counter-bored to accept the magazine cap so the cap was not
protruding from the wood. The magazine cap had detent notches on the rear
side that a spring loaded detent in the forearm counter-bore interacted with to
keep it from backing off.
Intermediate
Centurions, as with s/n A04905, used the newer carrier machined for the (2)
stamped extensions with a carrier extension that used two of the later single
type ones.
But they had a rivet at
the rear holding the two extensions together.
This configuration appears to be an intermediate version between the old
one piece cast extension but fitted to the new carrier that had a machined
spacer section to separate the extensions.
However the way the riveted extensions are made, they could have been an
early retrofit for the cast extensions IF a spacer was also used at the front.
The
later carrier extensions were simply a stamped out sheet steel, formed as
to made a RH and LH extension, with spacer (mentioned above) between
then at the pivot point where they are attached to the carrier. This
spacer separates these extensions so the hammer can move between them.
These slide arms have only (1) set of alignments pin,
while others have (2) at the silver solder
joint to the dog-bone.
In
the picture below, the bottom illustration shows a broken EARLY one piece cast
Centurion carrier extension. The middle one is for a Centurion or
Centurion II. The top one is for a model 82 as evidenced by the cut
out in the LH end. This will be explained in the 82
section. You will note that these lower 2 have bevels on both
edges. These extensions are shaped and beveled so they will slide
inside the spring tube housing.
Different carrier extensions | Shown on top is Wisner's conversion unit for the Centurion & model 82 |
|
|
Shown immediately above is a broken slide assembly off a model 82 |
Wisner’s Inc. , was making replacement Centurion slide assemblies.
The Centurion II and 82 have a completely different slide assembly.
Wisner’s makes a carrier that when used in conjunction with the
Centurion slide assembly, will allow this Centurion slide assembly to fit and
function in the Centurion II and the Model 82.
They also make locking blocks, extractors, firing pins, operating handles
etc. for these firearms, and some other discontinued Weatherby models.
The
slide tubes for the Centurion have an overall length of just the tubing of
5.14". Some
early slide tubes have (3) equally spaced holes of .203 dia., back .600 center line
from the front of the tube.
The
thought here was that it may act as an initial gas bleed off, however the gas is
trapped in the piston, but this may have been a secondary relief, as the later
tubes were about 1/8 shorter.
The
gas piston has no writing on it so can be installed upside down, however the
forearm can not be totally assembled if in this manner.
The
gas tube has a .065 dia. x .750 long retainer pin 1.535" in front of the
tube's base that screws into the magazine tube.
This pin keeps the gas piston from falling off during disassembly.
The hole for this pin is in line with the (2) gas port holes.
The
barrel for the 2 3/4" ammo has two (2) #37 gas holes. The magazine
cap uses a bleed of representing a cross with the arms .095" wide and
.330 overall length.
Centurion Action
Slide Bars ;
It has
been noticed that the notches cut out on the bars (normally .500) on a few guns
is a longer dimension
.555+-.
Known guns with the longer notches are s/n NA0094X, and another s/n
NA0268X.
One customer who has
one of these low numbered guns and it is still unfired in the box, says it
does not have a model on the end of the box, just “automatic”.
These s/n would have put them as transition Centurions make by Nikko,
while they were also being made by KTG, during 1973.
It is not known exactly when the change may have been made to the later
more common
.500 dimensions.
Also
on these early guns the slide bars were radiused on the rear.
The Patrician used a LH slide bar that was angled off on the rear to act
as a slide stop.
This necessitated
the need for 2 different bars in production.
Later they simply used the Patrician bars on both the guns.
However we have found that the first Centurions with the wider notch apparently
needed the shorter radiused LH bar end.
Slide assemblies for 82, Centurion II, & Centurion | Differences
between |
Good Centurion on top, center & bottom are damaged units |
In the photos above on the LH bottom is a Centurion slide
assembly with a original carrier in position. Above it in the center is a
model 82, on top is a Centurion II slide assembly. Center
photo shows the Centurion on the bottom, the newer type Centurion II and
model 82 on top. On the RH photo you can see a good Centurion slide
assembly on top with two broken ones below. The bottom one is
actually off a model 92 as evidenced by the flat angled rear and the notch on
the bottom on the RH bar. Most of the
Centurion breakages are one or both slide bars will break off at the rear
notches as shown above.
Bottom view of carriers, both semi-autos & pumps | Top view of carriers, both semi-autos & pumps | Centurion II gas system with forearm removed |
In the above Bottom Views photo, the top LH part is
Wisner's conversion carrier which in addition to a Centurion slide assembly,
converts to the Centurion II and model 82. Again in LH photo, left middle
is a original carrier for the
Centurion II and the model 82. Bottom
of same column is an original Centurion carrier. Note the shallow
groove lengthwise of it. This is the pad that cocks the hammer when
the action cycles rearward.
On the
RH side of the same photo are a broken model 92 on top with a original Patrician
on the bottom. The part that is broken on the 92 is the thin web that is
missing on the upper RH part of it.
In the above center views photo, the same parts are shown in same sequence as on the LH photo are shown, except flopped 180 degrees showing the top side view.
The RH
photo shows the gas system of a Centurion II, with the forearm removed.
Centurion II ;
The
Centurion IIs have the same receiver configuration as the regular
Centurions abd will have that model engraved on the LH side of the
receiver. Internally they are basically the same as the regular
Centurions, with the exception of an "improved" slide
assembly.
This
improvement is not really improved except it was easier for them
to make out of stamped parts. The tube was lengthened from to 6.14", was silver soldered to the slide arm stamping. The normal breakage here is that the the stamped metal slide bars will break at
or near the rear bend where they form a bridge and are connected to the
carrier.
This
gun also used a spacer of .233 front to back thickness with 1.157 dia. on the
magazine tube, against the receiver's front.
It appears this spacer acted as a dual stop, abutting against the rear of
the slide assembly tube and the front of the receiver.
This was timed so that the action bars are stopped at the same time the
rear of the carrier hits the inside rear of the receiver.
The forearm had a thin dual thickness C shaped metal liner of .500"
glued into the rear of the wood.
The
dual thickness involved the thinner part to blend in with the forearm's inner
hole and the rear thickness had a close fit over the above mentioned spacer.
The carrier was changed to match this
new stamped out slide assembly. The hammer was also changed to match the
combo of the slide assembly and carrier. The hammer was made lower from
the cocked notch to the cocking pad that the carrier rides over during the
cycling action. A Centurion hammer (being taller) installed into a
Centurion II trigger group will not allow the slide unit to move to the rear far
as it can not go deep enough in the II housing and will bind things to a stop.
The
Centurion II was made in either 2 3/4" or 3" barrels. The
2 3/4" barrels are the same as the corresponding Centurion barrels. We can not find any
difference in the gas system between the 2 chamberings other than possibly the
size and number of gas holes in the barrel for the 3".
The ejector is slightly different than the regular Centurions in that it's tail
was shorter by .200 and it does not have longitudinal grooves of the #3205.
The reason for the shorter ejector tail was apparently because these guns could
have been had in 3" where this one part could function for either depending
on the barrel it was fitted with.
Model designation on receiver of Centurion II | Top illustration is a model 82, with the bottom being from a Centurion & Centurion II |
Model 82 ;
These
guns were introduced in 1982, so possibly the reason for this model
designation??? These were made in either 2 3/4" only or 2
3/4" & 3" chamberings, with screw in
chokes while still using the ventilated rib barrels. The 2 3/4"
barrels use two (2) gas holes of #45 size while the 3" barrels use one (1)
size #45 hole. Both use the same magazine cap which has a
.250" dia. gas bleed off hole in the center. Barrels
appear to be available from 26" to 30".
The screw in
chokes were installed into a swaged up bore to accept the threading for these
chokes. These barrels are swaged up from about .830 (depending on
the length) to .905" at the muzzle to accommodate the internal threading
for the screw in chokes.
The 82 receiver was
again made of aluminum, but was slightly modified to a semi
hump-backed rear. Stocks
were pretty much the same configuration and design as the Centurion series
however they appear not quite as bulky. The forearm was shortened allowing
the magazine nut to protrude forward, which made it easier to take down as
compared to the Centurions.
The
slide assembly was again "improved" but again using the stamped, bent
sheet steel of the Centurion II but utilized a floating tube held in place by a
wedge. The tube was shortened to 2.50" long. It is common for
these slide assemblies to break at the pivoted wedge. Here the best
repair is to silver solder the tube to the bar unit.
Extractors
were the same as the Centurion series, however the plungers and springs were
made smaller. Firing pins and springs were also changed.
Year | Mfg Weatherby model Serial Number range Gauge |
1972 - 1974 | KTG Centurion Auto AO00001 - A07405 12ga 2¾” |
1973 - 1975 | Nikko Centurion “ NA00400 - NA10091 “ “ |
1976 - 1979 | Nikko Centurion II “ NA10884 - NA17754 12ga 2 ¾” |
1976 - 1979 | Nikko Centurion II “ NA10884 - NA17754 12ga 3” |
1979 - 1981 | KTG Centurion II “ A17755 - A18878 “ “ |
1982 - 1989 | KTG 82 Auto 82-00001 - 82-11527 12ga 2 ¾”/3” |
1972 - 1976 | KTG Patrician Pump SO00001 - S05089 12ga 2 ¾” |
1973 - 1975 | Nikko Patrician “ N00001 - N00011 “ “ |
1973 - 1975 | Nikko Patrician “ NS00500 - NS12863 “ “ |
1976 - 1981 | Nikko Patrician II “ NSI2922 - NSI8148 12ga 2 ¾”/3” |
1982 - 1989 | KTG 92 Pump 92-00001 - 92-11990 “ “ “ |
We have recently seen pictures of a
Nikko Super Express 7100 12ga in serial number range of J0039X that
appears to be an almost exact copy of the Weatherby Centurion.
The author does not have any source of parts for any of the firearms listed above
Copyright © 2004 - 2023
LeeRoy Wisner with credit given for original illustrations. All
Rights Reserved
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Originated 01-15-2006
Last updated 04-13-2023
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