I have owned my deactivated SMLE for nearly twelve years now and in all that time the rear sight has been held in position with a blob of blutak to stop it flopping around as the spring that tensions it snapped many moons ago before I bought it:
After all this time, I have finally bought a spare spring, in this case marked up as being made by Lithgow in Australia:
Fitting the new spring turned out to be a little trickier than I expected, so today I am going to run down how I did it in case you ever need to replace one!
The first job was to take out the stub of the old spring. Firstly I undid the little screw holding the spring in place:
The spring is dovetailed into the sight base, so I then used a small brass bunch and a hammer to gently tap it out backwards towards the butt and I was left with the broken spring and the screw (hang onto this carefully as it is very small and easy to lose:
With the old spring out it was time to insert the new one and this is quite tricky. The send of the spring needs to be depressed to allow it to slide under the sight whilst you tap it in far enough to allow the retaining screw hole to line up. The spring itself is too stiff to allow you to do this with hand pressure and you don’t have enough hands to do it anyway! The solution I found was to use a G-Clamp to compress the spring:
To protect the woodwork, I made sure the sling was between the bottom of the clamp and the rifle to stop it damaging the surface. The top of the clamp is too wide to fit over the spring so I improvised and used a small socket wrench bit to bridge the gap:
With the spring depressed, I could gently tap the spring back into place and when the screw holes lined up, secure it back in place with the little screw I had retained from earlier:
The little star indicating Lithgow production is easily visible here and although my rifle is a British made example, the parts are all interchangeable and I am most concerned about getting the sights functioning correctly which they now do after over a decade of waiting!
This was a fun little project and I always enjoy it when I can repair something and get it back to how it should be. As gunsmithing goes this is pretty minimal, but it was fun to do and my rifle is finally complete again.
Tales from the Supply Depot 
Good job, and good improvization, we’ll make an Armourer out of you yet 😉
I was cleaning out the parts bins once and came across a box of backsight assemblies.
We used the .303 until very recently, kept a few at various bases mostly for bears and also for testing the acoustic scoring system on the air to ground gunnery range since a 5.56 wouldn’t set them off and the FN’s had all been withdrawn. We kept the .303’s since we were a support Base for the Rangers at one time and until just a couple of years ago they were issued those.
Long story short, I remembered one of their Reg Force WO’s from the Small Arms competition we’d both attended, and sent him most of them along with a box of other spares we had far too many of and he was quite happy to get them.
Funny thing about the competition, one match was knocking 1 foot square steel plates off a beam as fast as you could. I ended up with one turned 90 degrees from a low hit with a 5.56 from a C7 and it was impossible to move after that, it cost us the match since we were way ahead at that point 😦 The .303 on the other hand, would throw the plate completely off the beam instead of barely knocking it over. If they’d fired a little faster and paid attention to their teamwork, the Rangers would have cleaned up on that one.
I enjoyed threading your article . I would recced for all things Enfield to contact John at DS Solutions. He is a font of all knowledge with regard to these weapons.
https://www.ds-solutions.co.uk/