• No42 and No53 sights …. Have you ever thought? (by Peter Laidler)

    The following article is published with the kind permission of Advisory Panel Member, Peter Laidler. Capt. Peter Laidler is the senior Armourer in the UK Military, now retired, but based as a Technical Officer at the UK Military Small Arms School. On behalf of MILSURPS.COM members, we'd like to publicly thank him for his support of this forum, as well the broader Lee Enfield collector community in general.

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    No42 and No53 sights …. Have you ever thought?

    Peter Laidler looks at the No42 and No53 sights and answers a few questions that you’ve probably asked in the past.


    Like me, you’ve probably thought quietly to yourself and asked many times this question. "If the No42 and 53 sights are optically identical and mechanically similar, then why can’t I use one as the basis for making myself a No32 telescope"?

    They’re certainly MUCH cheaper (although creeping up in price I admit………, but they’re certainly not the £5-600 or so price of a good No32 yet. Indeed, I’ve stripped a few for their optical spare parts value. Here are some of my thoughts. I’m not an expert in these things by any stretch of the imagination and accept that there are plenty out there who know more than me. I soon learned that the first person who reads what you’ve written IMMEDIATELY knows more than you do. That’s because he knows all that you’ve written plus the bit he knew before. Anyway, head above the mantlet and here goes……

    Taking a basic No42 or 53 telescope, here are the parts that are fully interchangeable with parts for your No32 telescope

    Ocular lens set and spacer, No42 (Mk1 and early Mk2’s)
    Ocular lens retaining ring, No42 (Mk1 and early Mk2’s)
    Ocular lens assy. with housing, No53 (Late Mk2 and all 3’s*)
    Erector cell assembly (All)
    Locking segment (All)
    Segment cover (All except some ‘2 screw’ Mk3’s)
    OG lens (Mk1’s and 2’s but **)
    Front shade (Mk1’s and 2’s only)

    * Can be used in Mk1 and early Mk2 if brazed inner collar removed
    ** While the OG lens will fit into a Mk3 tube, it is .038” or so undersize and therefore a sloppy fit. As such, it will always act as an eccentric lens and any zeroing will be at best, unreliable. At worst, crap!

    So there you have the parts that you can use in the future. But there’s a bit more than this. Because we’re looking at converting a 42/53 to 32 spec. Remember that this isn’t a comprehensive ‘how to do it’ but a guide of what you need to KNOW. First, we’ll look at the tube.

    THE TUBE The tube is almost identical to the Mk2 tube except in diameter. So to start with you’ll need to reduce the diameter of the tube to 1.000” where the tube sits into the No32 bracket cradles. The next thing we need to think about is what Mark/type of telescope we want. I have looked and pondered hard and decided in the interests of simplicity, we’re going to look at the Mk3 for many other reasons too, including cheapness.


    The business ends of a No32 Mk3 telescope (top) compared with the No43/52 ‘scope (bottom). It would appear that the shorter length of the No42 would make it incompatible with any conversion to Mk3 project but…………….


    (Click PIC to Enlarge)


    On the face of it, it seems as though you have got to increase the length of your donor tube to make it into the Mk3 length. That’s not the case at all because the inner sleeve (that houses the OG lens and grat on the No42/53) that you have removed from the front of the donor tube is what gives it its overall length in any case. If you continue to use this inner sleeve, albeit slightly modified (more later…..), you can also use the original OG lens and the front shade. It’s getting easier isn’t it?

    THE INNER SLEEVE. As I explained above, the inner sleeve is effectively the internal front part of the No42/53 that extends the shorter tube to give it it’s extra length. It also houses the OG lens assembly at the front and the graticle at the rear. To utilize this in our project so far, you must machine the rear end (smaller diameter) off squarely to give it a length of 1.75” approx from the front. Keep this rear end, you’re going to need this later. Waste not, want not as they say…………..


    Insert here photo 04 and caption
    04: But when the inner sleeve is inserted, it increases the length to EXACTLY that of a No32 Mk3. Additionally, using this sleeve, it ensures that the OG lens AND front shade can be re-used. Clever eh!


    But when the inner sleeve is inserted, it increases the length to EXACTLY that of a No32 Mk3. Additionally, using this sleeve, it ensures that the OG lens AND front shade can be re-used. Clever eh!


    (Click PIC to Enlarge)


    Next, we’ll talk about the bits that you’re going to need to complete the rest of this project and to help identify the parts, I suggest you look in the little telescopic sight book - wot I writ - some years ago! So find figure 12…………..

    Item 14 and or 26. 2x Mk3 drum assemblies
    “ 38 2x Guide shoes. Easy to fabricate in two parts from brass
    “ 49 2x spring for above. Purchase locally by the length
    “ 46 2x Plunger, clicker. Difficult to make and harden. Easier to purchase commercial self contained units or bore holes to accept 3mm balls and springs!
    “ 49 2x Spring, plunger. See comments above
    “ 2 1x Diaphragm. Easy to make and detailed in same book
    And last but not least, a brass turret housing……….! Are you still with me?


    Here’s the remainder of the parts that you’re going to need. All simply explained within the text


    (Click PIC to Enlarge)



    This is in fact a length of Mk3 graticle block or diaphragm, bored to size and marked with the post and cross wire position. Ready to be sliced into lengths, exactly .310” thick and hey presto, a dozen grat blocks for needy telescopes!


    (Click PIC to Enlarge)


    THE TURRETS This is where it becomes difficult and a tad expensive – unless you’re in the know - because the next thing is to find a good engineer equipped with a small CNC lathe. As well as being able to turn the parts of the range and deflection drums, he’ll know someone who can draw the parts up into CNC lathe readable format. It’s called back engineering.

    Different views of the Mk3 turret. This would be simplicity itself to cast, then pin and sweat onto the 1” diameter ex No42/53 tube. Machining is all 90 degrees to the other given a donor to back engineer from.

    (Click PIC to Enlarge)


    The good news about the turrets is that while they are different, it’s only the amount of rotation that differentiates between them. The range drum rotates through about 350 degrees while the deflection, about 160 degrees. But the internal difference that allows for this is minor and they are all but interchangeable. Dimensionally, the slipping scales are identical – it’s only the engraving that is different.

    Using those same back engineering facilities, those two same fine fellows will be able to draw up and machine the turret. The turret can then be pressed onto the tube, accurately pinned then soft soldered in place. Once the turret it fixed in place, then using the machined openings already in the turret as the datum points it’s a relatively simple matter to bore through the tube, opening up the range and deflection drum apertures. Rotate through 90 degrees and do the same, opening up the apertures for the spring loaded shoes on which the diaphragm or graticle block sits.


    Not a good photo, but none of mine ever are….. Shows the inner sleeve cut to 1.75” in length and the rear of the sleeve machined to .45”. This .45” length is going to be used as the rearmost of the two collars in which the graticle block or diaphragm will slide. Both pieces are shown in their relative positions. Waste not, want not……….


    (Click PIC to Enlarge)



    It’s that modified sleeve and collar again shown against an un-cut one. Don’t forget, FRONT section 1.75” long. REAR collar .45” long and just to reiterate, the FRONT COLLAR (see text) is 1” long.


    (Click PIC to Enlarge)


    Once this is done it’s time to position the two collars that accurately position the diaphragm/grat block in its correct optical position in the tube. You’ll remember that we’ve already got one of the collars, cut from the old No42/53 inner sleeve (see inner sleeve, above). This sleeve will be the REAR sleeve and must be shortened to .45” in length. You can either make another collar to the same diameters but 1” long or use another 1” length of another inner sleeve to make the FRONT collar The diaphragm slides up-down / left-right between these two collars. Positioning the collars is simple because these collars are positioned EXACTLY astride the dumpy lead screw nuts - attached to the range and deflection lead screws – that operate the diaphragm. Push the collars up to the lead screw nuts, pin or screw (they’re each secured with two 10BA c/sunk screws) and soft solder to secure.

    Deep inside the bowels of the Mk3 turret. Notice the two collars, sweated, pinned and (badly in this case….) staked in place. We’ve got the rear collar shown on the left but the front collar can easily be turned up out of brass or cut from another No42/53 inner sleeve.


    (Click PIC to Enlarge)


    That’s all there is to do……………………

    Copyright ©2006 - 2011 by Peter Laidler and MILSURPS.COM


    Collector's Comments and Feedback:

    1. Capt. Peter Laidler is the senior Armourer in the UK Military, now retired, but based as a Technical Officer at the UK Military Small Arms School. In addition to being a trained and highly experienced military "Armourer", he has authored two excellent books about the No.4(T) sniper rifles and their No.32 scopes. They are titled "An Armourer's Perspective: .303 No.4(T) Sniper Rifle", which he co-authored with Ian Skennerton and his own dedicated work, "Telescope Sighting No.32".

    If you're really interested in some in-depth learning about the No.4(T) sniper rifles and the No.32 series of scopes, their history, evolution, repair and adjustments for shooting, I'd highly recommend those two books, which are pictured below.
    ....... (Feedback by "Badger")


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    Note: The opinions expressed herein or statements made in this article are solely those of the author, and do not necessarily reflect the views of the Military Surplus Collectors Forums, or the ownership and moderation group of this site. MILSURPS.COM accepts no legal liability or responsibility for any claims made or opinions expressed herein. Also, please note that neither the author nor MILSURPS.COM recommends that any member of these forums, or a reader of this article, try this type of experimentation without the proper knowledge, equipment and training.
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