Service notebook of Harold Gordon Cornell - 1917 - Part 12

7.

.303 Lewis Automatic Machine Gun

position for the bolt in the forward movement.

Forward Movement

(7) Release of Sear

If the trigger is pressed the nose of the sear is

dis-engaged from the bent on the piston rod. The return

spring unwinding, the pinion carries the piston rod, and

striker post forward by means of the rack on the piston

rod. The striker post carries the bolt forward by the 

left side of the striker post bearing against the left side

of the curved camway groove.

(8) Placing of Cartridge in Chamber, and locking of Bolt.

As the bolt comes forward, the top extractor hits the

lower rim of the cartridge which is protruding into the

feedway, knocking it forward & downward into the

chamber. The extractors then spring over & grip the rim

of the cartridge which is prevented from going too far

into the chamber by the register. As the bolt moves

forward it strikes against the front of the ejector &

forces the rear-end into the bolt way. The rear end of

The left side of the striker post bears against the left side

 

8.

.303 Lewis Automatic Machine Gun

of the curved camway groove, turning the bolt one-eighth

of a turn to the right, locking the resistance lugs

in the locking recesses. The sticker pool has now to

travel along the straight path of the camway groove

1 1/8" before the cartridge can be primed. This is a

safety device to ensure that the bolt is fully locked

before the cartridge is primed. When the gun is fired,

the resistance lugs, bearing against the locking recesses.

take the shock of discharge.

(9.) Priming of Cartridge.

The striker post having travelled along the straight

path of the camway groove a distance of 1 1/8", the striker

post enters the striker way in the face of the bolt &

primes the cartridge.

(10) Action of Feed aim & Pawls.

During the forward movement of the bolt, the boss

on the actuating stud, working in the groove on the under

side of the feed arm finger, carries the feed arm from

right to left to right. The feed pawl passes over the

next projection & engages in the next indentation of the

 

9.

.303 Lewis Automatic Machine Gun

magazine. The feed pawl spring stud bears against the

right stop pawl and forces it out of action, allowing the

magazine to be rotated. The left stop pawl remains

stationary & prevents the magazine from rotating counter-clockwise.

Points to be examined before taking gun into the air

(1) Large hole of gas regulator to the rear

(2) Mounting yoke with pin in right hand side with

handle to rear & turned down.

(3) Deflector bag securely fixed & bottom flap fastened.

(4) Cocking handle in correctly.

(5) Return spring correct tension (about 11 lbs)

(6) Cartridge guide spring functioning as a spring.

(7) Correct sight securely fixed.

(8) Fire 20 rounds into the ground.

Spare tools to accompany gun

(1) Spring Balance             (2) Cartridge Guide Spring.

(3) Armourer's Dummy       (4) Loading handle

(5) Device for pulling back  (6) Screwdriver

cocking handle                         (S.C.A.L.D.S.)

 

10.

.303 Lewis Automatic Machine Gun

Care of Guns

Oil. Special oil for low temperature known as

"P. 924" Failing this a mixture of Rangoon & Instrument Oil.

When in store Strip body group every day & clean

barrel & gas cylinders. Strip gun right down once a

week. Clean all parts & lay out for examination &

reassemble. Spare parts to be wrapped in oily paper &

kept in wooden box: lay out for examination once a week

pack & replace in oily paper.

When the gun has fired less than 600 rounds, strip body

group & clean barrel with oil & 4" x 2" flannelette & rod.

Clean gas cylinder with wire brush, oil, & then dry mop.

Always take out extractors after firing so as to clean face

of bolt. When gun has fired more than 600 rounds,

strip gun completely, pour boiling water down the barrel,

gas cylinder & guide ways. Clean all parts, thoroughly dry

& reassemble. Care should be taken to keep dry all

portions which are subjected to the action of powder gases.

Parts to be well oiled Piston head & rings. (N.B. Cupped

head, never to be oiled) striker post & camway, locking lugs &

recesses, feed aim channel, magazine post.

 

11.

.303 Lewis Automatic Machine Gun

Parts to be lightly oiled.

All threads & worms, pawls, skids, & springs, pinion, edges

of return spring and rack, surface of bolt, proof of

ejector, body ribs, guide grooves.

Parts to be examined for wear

Left hand guide lug on actuating skid feed arm channel,

resistance lugs extractors (broken or weak) cartridge guide

spring, gas cylinder (not bent or broken), striker post

& camway. N.B. Look for burrs.

Care of Magazines

Magazines must be emptied, cleaned, tested, &

refilled, once a day, especially after a flight.

Testing magazines Place magazine on loading handle.

& rotate. See that it is running truly & freely. If stiff

clean with petrol & re-oil.

Place magazine on magazine pool and rotate slowly

and examine diameter, test catch, & spring, & examine

separating pegs for tightness & uprightness, & tip of centre

block is not bent or broken.

 

12
.303 Lewis Automatic Machine Gun
Testing Ammunition
Examine for dents, thick rims, bulged rounds, sunken caps,
split cases.
Test each round in Spare Lewis gun barrel (new).
Keep tested ammunition apart from untested & get rid
of all defective rounds; also keep "Tracer" ammunition.
apart from ordinary.
Stripping
1. Spade Grip           9. Pinion Group            17. Rear Radiator Casing
2. Body Cover         10. Body                          18. Gas Cylinder
3. Pistol Grip           11. Ejector Spring Cover  19. Gas Chamber
4. Feed Arm            12. Ejector                        20. Barrell Mouthpiece
5. Cocking Handle         13. Gas Regulator Key       21. Barrell
6. Bolt                             14. Gas Regulator              22  Barrel stand
7 Pistol Rod                    15. Radiator Clamp Ring    23 Radiator
8  Body Locking Pin        16. Front Radiator Casing

 

 

13.
.303 Lewis Automatic Machine Gun

Springs.

Return Spring                                     Flat Coiled Spring
Pinion Pawl Spring                             Wire Spring
Butt Latch Spring.                               Spiral Spring
2 Extractor Springs                             Flat Spring
Ejector Cover Springs                         Flat Spring
Feed Arm Pawl Spring                        Wire Spring

Stop Pawl Spring                                 Shaped Steel Spring
Cartridge Guide Spring                        Ribbon (shaped) spring
Tangent Light Spring                            Flat Spring
Milled Head Check Spring                    Wire Spring
Plunger Spring                                      Spiral Spring
Magazine Catch Spring                        Flattened Spiral Spring.
C.T.B
2nd LIEUT,
Officer i/c Lewis Gun Inst'n
S. of M. A. 

-Magnetos-

Magnets of Tungsten steel
Diagram ~ see original document

Section of Armature

Diagram ~ see original document
 

-Photography- 

Camera is fitted to machine by means of a cone shaped
fitting with which the camera is securely fastened.
and which is attached to two wooden struts
fastened to top & bottom longeron on machine.
where possible the whole fittings are then strapped together
The best height for taking photographs is
6000 to 7000 ft. ; this covers a 1000 yds square
in a 1/20000 map, also arial conditions are best 
at that height.
Before a photographic flight
See camera is properly adjusted i. e. lens clean; shutter
slit adjusted ( ½" to 1"); Tension fully wound; shutter 
set; plate indicator set at zero; fit on charger
boxes with draw slides & clip back.
During a photographic flight

Ride with machine dead level over spot, against
wind. engine throttled down to avoid vibration To take photograph, see handle is fully
with drawn, shutter set (see set wheel); pull release
this takes photograph. To change plate & reset
shutter press forward handle, 2/3 of way, gently

 

-Photography- 
R.F.C Changer Box Camera

then push home very firmly & withdraw with a bang.

After a photographic flight

Pass all remaining plates into the expressed plate
box & close slide; release tension; deliver plates
to photographic section with report; report must
contain map reference for each plate exposed, date
time of day, flying ht; gen weather conditions, type
& number of machine.
To sight camera Use special sight if possible, or
sight down camera fitting; space between
fuselage & camera, gives good guide to area photographed.
Diagram ~ see original