Updated: Jan 20
Of Front Sights
The front sight blades on all Lee Enfield Models were fitted using a vee-groove - of very similar sizes over 120 years. The front sight blade could be adjusted in this vee-groove to correct for windage (by tapping the blade left or right), there were versions of a screw based adjusting tool - these are not necessarily as fast or effective as a calibrated tap with a hammer! The front sight blade was also incremented in 0.015' height increases to be switched for elevation adjustments - the original and official sight blade size range for the SMLE was from -0.030" to +0.090" (referenced to the sight block "above barrel centerline datum".
There are four major derivatives of No4 Rifle Front Sight Blades, of which the #1 and #1* versions were the earliest and experience in the desert showed that the rear edge, which was chamfered upwards could reflect a line of light into the shooters eye.
The #2 and #3 versions used a downward facing rear chamfer to stop reflected light.
The #2 sight blade is the only version specified for the No4T rifles using a split front sight base with clamping screw.
The #1* and #3 versions posses a split base which was to be used in the war expedient (and for later models standard) solid sight bases - these were introduced mid-war as a manufacturing expedient and for the reduction of the complex clamping screw. These split blades have been termed as "universal" to all Lee Enfields in some circles as they can be squeezed into all (most) sight bases and clamp functionally retain themselves. I recommend #3 versions for use in No5 Jungle Carbines as the solid ones seem to be too loose in these..
Here are some Fazakerley made and marked Front Sight Blades showing -0.030 through +0.090 sizes and a mix of Mk2 and Mk3 designs
Marked for size per the No4 rifle datum (the same datum was used on the No1 SMLE blades and rifles also). Marked for factory of manufacture:
B - BSA
CA - Canadian Arsenals
F - Fazakerley (Faz)
L over B - Longbranch
M - Matlby
N67 - Singer Machine
P - Poole
S - Savage
S in Square - Stevens Mfg (Savage subcontract)
S.M. - Singer Machine
Longbranch (CA) and Savage examples used a relaxed specification for blade body width and are notably wider than British produced front sight blades.
When adjusting zero for your rifle - add a taller sight blade when Point of Impact is high and a shorter blade when POI is low. For a 303 Mk7 rounds I have observed around 3 inches of elevation / depression change at 100 yards for each size of front sight (0.015”). For 308 (Nato 7.62 x 51) rounds I have observed 2 inches of elevation /depression.
The Pattern (19)14 (No 3) and Model of 1917 rifles have a sight datum 0.060" higher over the barrel centerline so minus -0.060" to the stamped sizes on blades for use with these rifles to find an SMLE equivalent size.. A +0.015 No1/4 blade is equivalent to a +0.075 P14 / M17 blade.
The SMLE sight blade was also used on the STEN designs throughout the war. The range of production on the STEN also necessitated the introduction of blade graduations above 0.090 sizes - so the 0.105 and 0.120 sizes were added as STEN only in British / MoD use - but in the aftermarket and private uses these sizes fit and are useful on all the models of Lee Enfield Rifle and Carbine too.
Of Rear Sights:
Here is the No4 Rifle Micrometer Rear Sight which was part of the original Trials Rifle design in the 1930's and was built for the initial production rifles but war time production expedient modification replaced it with 3 versions of simplified sight on all but No4T designated production rifles until factories and efforts could keep up. The design and first versions of this sight were produced by the Singer so it was also known as the "Singer Sight". The micrometer rear sight was to be switched onto any rifle in FTR or armourer rebuild in place of the simpler versions in the post war years. The No4 Micrometer rear sight can be used with todays sports load ammunition and to attain a 100 yard effective zero - each click is 2 MOA on the standard screw and indent spacing. If the rifle is zeroed effectively at the 200 yard setting with Mk7 ball then the micrometer sight can be found to have 2 to 4 clicks still available below the the 200 yard graduation. So clicking down can get you on target at shorter ranges. I count all my clicks for range adjustment!
The No5 Carbine was developed from the No4 Rifle, however with its shorter sight radius the micrometer sight needed recalibrating - this was done by making the micrometer screw of a different thread pitch (and diameter) than the rifle version to give the right adjustment per click. Another indicator of carbine format micrometer parts is the micrometer screw is not threaded over its entirety - just half way - this supports the indicated ranges on the carbine ladder body being from 200 to 800 yards.
The last generation of the Singer Sight was in the hands of Parker Hale for the M84 Sniper Rifle program. They seems to have used Rifle and Carbine sight ladders and added a Meter calibrated scale on the side of the ladder - read off the inner bottom edge of the left cursor window.. The micrometer screw was modified to have 12 notches - which gave 1MOA increments of adjustment. The cursor screw was then peened into the cursor upon assembly to tighten its fit and prevent backlash. The ladder body had a larger cross hole drilled to accommodate a windage clicker screw which was housed in a custom mounting plate - giving 2MOA windage adjustments.
These Micrometer sights are easily rebuilt and serviced - I often switch a PH 1MOA micrometer screw, nut and cursor onto a standard ladder to make a more precise sight for sports shooting.