Rifle, Calibre .22, C NO 7, MK 1, W/E 1005-21-109-2624

  Issued on Authority of the Chief of the Defence Staff

  1984-09-14

  Table of Contents

  Part 1 – Introduction
  General

  Part 2 – General Description
  Introduction
  Basic Description
  General Characteristics
  Barrel Assembly
  Front Sight
  Bolt Assembly
  Body
  Trigger Guard and Trigger
  Safety Catch
  Back Sight
  Butt Assembly
  Forestock Furniture
  Magazine

  Part 3 – Theory of Operation
  Introduction
  Loading and Cocking
  Firing
  Extraction
  Action of the Safety Mechanism

  Part 1
  Introduction

  General
  1. This CFTO details the description and theory of operation of the Rifle .22 Calibre, C No 7, Mk 1.
  2. Any observations, comments or criticisms which would assist in increasing the value of this publication should be addressed to:

  National Defence Headquarters
  Ottawa, Canada
  K1A 0K2

  Attention: DLAEEM 2-2

  Part 2
  General Description

  Introduction
  1. Use of standard calibre rifles as personal weapons generates considerable training expense.
  In order to reduce expenses when teaching range and handling practices to personnel,
  it has been the habit of many armed forces to convert these weapons to a smaller calibre in order to reduce costs.
  Programs adapted in the early 1990’s involved converting .303 calibre rifles to .22 calibre.
  One of the first such conversions was of the Lee Metford MK 1 rifle in 1907.
  These conversions carried forward from the Long Lee Enfield in 1911 and the Short Magazine Lee Enfield in 1912,
  through a series of intermediate weapons, to the .22 calibre conversion of the rifle, calibre .303, No 4 Mk 1.
  Some of these conversions involved fitting of new barrels while others required reboring and fitting of barrel inserts.
  The majority of these weapons requires special bolt heads.
  The Rifle, .22 Calibre, C No 7, Mk 1 is a single shot version of the Lee Enfield Rifle, .303 Calibre, No 4, Mk 1 Star weapon.
  This weapon was produced for the Canadian Armed Forces by Canadian Arsenals in Long Branch Ontario.
  A five shot version was produced by the British for their own use.

  Basic Description
  2. The physical design and appearance of the .22 calibre, C No 7 rifle is generally the same as that of the .303 calibre, No 4, Mk 1 Star, with these additional features and changes:
     a. Feeding – The C No 7 rifle is a single shot, hand fed weapon.
    The magazine platform serves only as a guide for the cartridge.
    b. Back Sight – The back sight is adjustable both laterally and vertically.
    It is graduated for two ranges: 20 yards and 100 yards.
    c. Bolt – Outwardly, the bolt appears identical to the No 4, Mk 1 Star bolt.
    But the C No 7 has a shortened striker with a separate firing pin, and the firing pin hole is offset in the bolt head to accommodate the rim-fire characteristic of the .22 calibre cartridge.
    d. Barrel – The barrel is essentially the No 4 barrel bored and rifled for .22 calibre ammunition.
    It has no bayonet lugs.
    e. Magazine – The magazine platform is grooved and inclined toward the rear.
    It has a cut-away at the rear that will allow empty cartridges to fall into the magazine.

  General Characteristics
  3. The Rifle, .22 Calibre, C No 7, Mk 1 is comprised of the following major sub-assemblies: barrel and front sight, bolt, body, back sight, butt, and forestock furniture.

  Barrel Assembly (Figure 2-2)
  4. The barrel is a one-piece steel machining with a 6 groove bore.
  The exterior is cylindrical with an oversize tapered reinforce at the breech end, that provides one flat for clamping during breeching of the barrel.
  The reinforce is formally named the Knox or Knoc’s form after the early gun maker that originated this means
  (that is a single flat at the breech aligned with the front sight) of assuring correct sight alignment during breeching.
  The breech end of the barrel is threaded to screw into the body.
  Correct sight alignment is facilitated by adjusting the torque applied to the barrel during breeching.
  The breech face of the barrel is machined to provide a clearance for the extractor.
  Most barrels have one set of lugs provided at the muzzle end to position the front sight block band, which is secured by a lateral pin at the top of the barrel.
  However, some barrels have no lugs.
  On these barrels, the front sight block band, is secured by two lateral pins, one at the top and one at the bottom.
  The barrel is generally supported at both ends, at the breech end by the body and at the muzzle end by the front bearing of the fore-end stock.
  However, some weapons after repair or overhaul may be found to have been centre bedded.
  In which case the barrel is supported at the rear by the body and at the barrel midpoint by a fitted composition bearing.
  The barrels of these centre bedded weapons are free floating for 360 degrees at the muzzle end of the fore-end stock.

  Front Sight (Figure 2-3)
  5. The front sight on the C No 7 is of the vertical blade type.
  All adjustments to vertical displacement of the MPI are made by changing the front sight blade.
  The blade is available in 12 sizes ranging from -0.045 inch to +0.120 inch in increments of 0.015 inch, see Figure 2-3.
  The blade is supported in the lateral dovetail slot of the front sight block band, and secured upon assembly by a set screw.
  The front sight block band is fitted with a removable front sight protector.
  The majority of these front sight protectors are roughened on the top and rear by knurling or serrations, as a means of reducing glare from reflected light.

  Figure 2-3 Front Sight Blade

  Bolt Assembly (Figure 2-4)
  6. The bolt assembly is comprised of the bolt body with integral handle, firing pin, firing pin rod, firing pin rod spring, cocking piece, bolt head and extractor assembly.
  The bolt body is a one-piece machined forging that incorporates a cocking handle and locking lugs on a basically cylindrical body.
  It is slotted externally at the rear to accommodate the lug of the cocking piece and threaded internally at the front to accept the bolt head.
  The bolt houses the firing pin assembly is comprised of a firing pin rod and firing pin.
  The firing pin rod is inserted through the firing pin spring and threaded into the cocking piece at the rear of the bolt.
  The bolt head is threaded to screw into the bolt.
  The head compensates for manufacturing tolerance and wear in the locking surfaces of the bolt body.
  It is available in six sizes numbered from 0 to 5.
  The sizes are stamped on the top flat.
  The head is secured in the weapon by a slot on the bolt head lug.
  This slot interlocks with a track on the right side of the body.
  The head houses a spring loaded extractor.
  The extractor and spring are mounted in a slot in the bolt head on a lateral axis screw.
  The cocking piece screws onto the rear end of the firing pin rod and is secured by a screw.
  It has two notches on the left side that interact with the safety catch when applied.
  The bottom of the forward notch is machined across the bottom face of the cocking piece to provide a half-cocked notch of the trigger.
  The forward face of the cocking piece acts as the full-cocked sear bent.

  Figure 2-4 Bolt Assembly

  Body (Figure 2-5)
  7. The body is threaded in the front to accept the barrel and formed as a housing in the rear to accept the butt assembly.
  The body is machined with guideways at the top and bottom that lead forward to the locking recesses.
  These guideways accept the locking lugs of the bolt.
  The bolt path in the body is open at the top except for the bolt bridge.
  The bridge is welded to the projecting shoulders of the body to add rigidly to the component.
  The forward portion of the right side of the body is machined to allow a clearance for hand loading rounds.
  The bottom of this clearance has a track machined as a guideway for the lug on the bolt head.
  A cut-away in this track facilities removal of the bolt by allowing the bolt head to be rotated to the vertical, in line with the bolt column.
  The body is equipped with the ejector screw even though the screw serves no function, since the smaller calibre rounds are not large enough to contact it.
  Projecting tabs at the bottom middle of the body provide the mounting points for the sear and magazine catch.
  The sear operates on a lateral axis pin under spring pressure.
  The sear spring also provides the pressure required to operate the magazine catch which is mounted on a lateral axis pin immediately forward of the sear axis pin.

  Figure 2-5 Body Assembly

  Trigger Guard and Trigger (Figure 2-6)
  8. The trigger guard is secured to the bottom of the body by two screws, one vertical screw at the front that threads up into the bottom of the breeching thread boss of the body,
  and one horizontal screw at the rear that threads into two lugs at the bottom of the butt housing of the body.
  The forward screw is equipped with a sling swivel.
  The forward end of the trigger guard is machined to accept the magazine.
  The rearward portion above the trigger guard is machined with a longitudinal slot that accommodates the trigger and magazine catch.
  The trigger operates on a lateral axis pin in the trigger guard.
  It is a one-piece machining with two actuating ribs.
  The lower rib provides the first pull, the upper rib provides the second pull.

  Figure 2-6 Trigger Guard and Trigger

  Safety Catch (Figure 2-7)
  9. The safety catch is housed in the left side of the body at the rear.
  It is a two-stage mechanism comprised of a safety catch and a bolt lock.
  The safety catch mounted on the helical spline of the bolt lock.
  Figure 2-7 Safety Catch

  Back Sight (Figure 2-8)
  10. The aperture back sight is a folding leaf type sight with lateral and vertical adjustment.
  The angular adjustments to the line of sight are in one minute clicks.
  The lateral adjustment screw is graduated on the head with six equally spaced white lines, these represent half minute lateral movement of the sight.
  A corresponding white line is cut in the left shoulder of the body.
  The leaf is graduated for two ranges, 20 yards and 100 yards.
  A line is cut in the slide to correspond with the range lines on the leaf.
  The slide is drilled and threaded to accept a sight aperture.
  The one minute of angle clicks are regulated by notches cut in the inside face of the elevating screw knob and the inside face of the windage screw knob.
  A spring and plunger engage in the notches of the elevating screw.
  A leaf spring, that is secured to the body by a small screw, engages the notches of the windage knob providing a click for every one minute of adjustment.

  Figure 2-8 Back Sight

  Butt Assembly (Figure 2-9)
  11. The butt assembly of the C No 7 rifle comprises the buttstock wth a butt plate, sling swivel, and securing bolt.
  The buttstock is manufactured from seasoned walnut, birch or beech, in four lengths.
  These four lengths, long, normal, short and bantam allow changes in the length of the butt assembly in ½ inch increments.
  The end of the butt is covered by a cast or forged butt plate that is secured by two wood screws.
  The plate has a spring loaded trap that covers the two storage holes in the butt.
  The butt is secured to the body of the weapon by a bolt inserted through the larger of the two storage cavities.
  The bolt is locked by a double helix lock washer that bears against a flat washer on the shoulder in the butt.
  There is a sling loop located at the lower end of the butt.
  This sling loop may be of various design, and is attached by a machined or stamped metal bracket.

  Figure 2-9 Butt Assembly

  Forestock Furniture (Figure 2-10)
  12. The body and barrel of the C No 7 rifle are covered by wooden furniture manufactured from walnut, birch or beech.
  The stock fore-end encloses the bottom of the barrel and either side of the body.
  It is attached to the body by the same screw that secures the front of the trigger guard assembly.
  It extends forward from the butt housing to the front sight.
  The top of the barrel is enclosed by two handguards.
  The rear handguard is secured at the rear by a metal ring on the barrel and at the front by the sling band.
  The front handguard is secured at the rear by the sling band and at the front by the upper band assembly.

  Figure 2-10 Forestock Furniture

  Magazine (Figure 2-11)

  13. The magazine is a box shaped metal casing fitted with a spring loaded platform.
  The box has a tapered rib at the centre of the rear face that engages the magazine catch.
  The magazine platform is formed with two ribs to facilitate hand loading of the weapon.
  The rear of the platform is cut-away to allow empty casings to fall into the magazine since the ejector does not function with these smaller calibre rounds.
  This magazine is identified by the figure 22 stamped on the left side of the casing.

  Figure 2-11 Magazine

  Part 3
  Theory of Operation

  Introduction
  1. The C No 7 rifle is manually operated and fired from a closed and positively locked breech.
  The description of the mechanism action begins with the bolt fully rearward and an empty magazine in place.

  Loading and Cocking
  2. With the bolt pulled fully rearward, the platform of the magazine is completely exposed.
  A single round is inserted into the chamber, and the bolt is pushed forward.
  The forward travel of the bolt stops at the bottom of the cocking piece contacts the sear.
  Forward pressure on the cocking handle moves the bolt and compresses the firing pin spring until the locking lug contacts the inclined locking ramp of the body.
  Forward and downward pressure on the bolt handle cams the bolt fully forward into the locked position.
  The locking faces of the bolt column and the locking lug bear evenly on the locking surfaces in the weapon body.

  Firing (Figure 3-1)
  3. Rearward pressure on the trigger brings the lower rib of the trigger into contact with the lower leg of the sear.
  The sear is rotated downward and the upper leg of the sear moves down across the face of the cocking piece.
  The action continues until the sear approaches the lower edge of the cocking piece sear bent, at this point the upper rib of the trigger contacts the lower sear leg, see Figure 3-1-A.
  This is the first pull of the “double pull” action of the trigger.
  The pressure required to continue trigger action now increases as the second or upper rib of the trigger comes in contact with the lower arm of the sear, see Figure 3-1-B.
  With the trigger fully depressed, the upper arm of the sear is disengaged from the bent of the cocking piece, see Figure 3-1-C.
  The cocking piece and the firing pin rod move forward under the influence of the firing pin spring.
  The firing pin rod forces the firing pin forward to strike and fire the cartridge.
  The locking faces of bolt column and locking lug bear evenly on the body locking surfaces to transfer the shock of the fired cartridge directly ant equally to either side of the body.

  Figure 3-1 Firing

  Extraction
  4. When the cocking handle is rotated upward, the bolt is automatically cammed to the rear by the profiles of the body grooves.
  This camming action withdraws the bolt approximately 1/8 inch to complete primary extraction.
  At the same time, the stud on the cocking piece moves from the long to the short groove in the bolt and it is forced rearward approximately 1/8 inch to withdraw the firing pin rod.
  Final extraction is completed upon rearward movement of the bolt.

  5. The extractor is enlarged over the rim of the casing. As the bolt moves rearward the extractor withdraws the casing from the chamber.
  Due to the reduced calibre of these cartridges the extractor will not hold onto the casing once it leaves the chamber.
  However, with the weapon tilted slightly upward, the casing will drop away from the extractor and slide rearward to the cut-away in the magazine platform where it drops into the magazine case.

  Action of the Safety Mechanisms
  6. Applied Safety – The safety catch (bolt locking assembly) may be applied with the cocking piece in either fully cocked or firing position.
  When the safety catch is applied, two distinct and separate actions take place at the same time.
  The half round projection on the locking bolt rotates upward into one of the notches on the cocking piece,
  the forward notch in the cocking piece is cocked, and the rearward notch if the cocking piece is in the fired position.
  The locking bolt when engaged in the cocking piece prevents movement of the cocking piece.
  At the same instant that the locking bolt is engaging the cocking piece, the safety catch, which is mounted on a course spline on the locking bolt,
  is being forced inward into a cut-away on the left side of the bolt.
  This prevents the bolt from being rotated out of the locking position.

  7. Interaction of the Locking Bolt and Safety Catch – The action of the rifle can only be effectively safe-guarded when both of these components are in place and working properly.
  If the weapon is assembled without the safety catch in place, the weapon can not be fired if the locking bolt is applied.
  But, the bolt can be unlocked and the breech opened approximately one inch, as detailed in Figure 3-3, if the cocking piece is in the cocked position.
  The locking bolt and cocking piece, being locked together, will prevent further rearward movement.

  Figure 3-3 Action of the Locking Bolt Without the Safety Catch

  8. Built-in Safety – The half-cock notch on the cocking piece is the built-in safety feature of this weapon.
  When the cocking piece and sear are engaged at the half-cocked position, the weapon may not be fired.
  Neither may the breech be opened, until the cocking piece is drawn to the fully cocked position.

  9. If the bolt has not been properly closed and locked when the trigger is pressed, one of two things may happen.
  The stud on the cocking piece may close the breech by striking the rounded corner of the division between the two grooves on the underside of the bolt at point “A” of Figure 3-2.
  This will cause the bolt to turn down closing and locking the breech.
  Or, the stud on the cocking piece may strike on the flat of this division between the grooves, at point “B” of Figure 3-2.
  This will prevent the striker from moving forward far enough to fire the cartridge.
  Closing the bolt at this point, with the trigger released, will result in the cocking piece moving forward over the sear until the sear enters the half-cock notch.
  This results in the action becoming locked.
  The trigger can not be pressed and the breech can not be opened until the action is returned to the cocked position by pulling the cocking piece fully rearward.
  This interaction, between the cocking piece stud, the bolt track and the cocking piece half-bent,
  acts as a safety feature to prevent the rifle from being fired when the breech is not fully closed and locked.

  Figure 3-2 Safety Feature – Bolt and Cocking Piece