Parts Guide
Retrieved: 06/01/2014

PARTS LEGEND No1 MkIII

1. Receiver
2. Stock Bolt
3. Magazine Cut Off
4. Magazine Cut Off Screw
5. Magazine Latch
6. Sear/Magazine Latch Spring
7. Sear
8. Trigger
9. Trigger Pin
10. Magazine Latch Pin
11. Bolt Head Spring
12.Bolt Head Spring/Sear Screw
13. Bolt Head
14. Extractor Screw
15. Extractor
16. Extractor Spring
17. Ejector
18. Bolt
19. Firing Pin (Striker)
20. Main Spring
21. Cocking Piece
22. Firing Pin Lock Screw
23. Safety
24. Safety Stop Washer
25. Bolt Lock
26. Safety Spring
27. Safety Spring Screw
28. Trigger Guard
29. Magazine
30. Front Guard Screw
31. Rear Guard Screw

SMLE (No1 MkIII)

1. Receiver
2. Stock Bolt
3. Stock Bolt Washer
4. Ejector
5. Bolt Lock
6. Safety Spring Screw
7. Safety
8. Safety Spring
9. Extractor
10. Extractor Screw
11. Extractor Spring
12. Bolt Head
13. Bolt
14. Firing Pin
15. Main Spring
16. Cocking Piece
17. Firing Pin Lock Screw
18. Sear
19. Sear Pin
20. Trigger
21. Trigger Pin
22. Sear/Magazine Latch Spring
23. Magazine Latch
24. Bolt Head Release
25. Bolt Head Release Spring
26. Bolt Head Release Stop
27. Magazine Latch Screw
28. Trigger Guard
29. Rear Guard Screw
30. Front Guard Screw
31. Magazine Box
32. Follower Spring
33. Follower

No 4 MkI

This image shows the positioning of the Lee-Enfield safety/locking bolt in the cocked and uncocked positions.

A - Bolt head,
B - Extractor,
C - Bolt head lug which housed the extractor and extractor spring,
D - Bolt guide rib/locking lug
E - Cocking piece,
F - Left locking lug and
G - Gas vent hole in the bolt head

Headspace adjustments can be easily accomplished with the Lee-Enfield, simply by replacing the bolthead. As the Enfield rifle was a military, combat designed rifle there are actually two sets of specs listed for headspace. These are:

Remember, the .303 is a rimmed cartridge, so headspace is the distance between the bolt face and the cartridge rim. Unlike the rimless cartridge, which draws its headspace from bolt face and the cartridge shoulder.

For the SMLE/No1 family of Enfield's adjusting headspace can be accomplished by swapping different boltheads until one is found to produce the desired distance. This is necessary because the SMLE was only manufactured with one size of bolthead and the unit armourer stoned the bolt face to correct for headspace.

In designing the No4/No5 family of Enfield's, this minor headache was cured by producing 4 different bolthead sizes. This allowed the unit armourer and now the private owner to simply select the correct bolthead to quickly adjust headspace to specs.

Each No4/No5 bolthead is numbered either 0, 1, 2, or 3. Each number specifies an increase in length, nominally .003 of an inch.