Need help with my Telescope L1A1

Hello everybody from cold and dark Austria.

Played with my telescope L1A1 from my L42A1 this afternoon in preperation for boresighting and zeroing the rifle. At the moment the telescope is removed from the bracket. After I centered the elevation and deflection turret as discribed in Capt Laidlers book I saw by bringing the horizontal line of the graticule exactly horizontal, the upper surface of the elevation drum is not horizontal, it differs a little bit to the right.
Can this be correct?

I have to add that rifle, bracket and telescope are cross referenced with all numbers matching.

Mmmmmmm. Several questions first Frank. Are you saying that
The graticle post and crosswire are SQUARE to each other but the crosswire does not appear to be parallel with the range or square to the deflection drum? On the face of it, this would appear to indicate that the graticle post and crosswire are not square in the diaphragm (or grat block) but this is highly unlikely in my opinion.
OR; that when the telescope is mounted in the bracket, fitted to the rifle, with the foresight protectors upright and square to a surface plate that the grat/grosswire is not square or they ARE square on BUT
Is it the top of the range drum that isn't square?

Crosswires are sweated on against a laid-out square on the table against the edge of the diaphragm under a lage magnifyer and somethines, due to the curvature of the glass, it looks like the graticle post is not square on or even bent or even that the crosswire if raised at each end (like a skipping rope).

The IMPORTANT thing is that the post and wire are square to the RIFLE bore. Even then, if they weren't exactly square-on to the rifle (and I'm thinking on my feet here.......) it would be of academic interest only because the purpose of the crosswire is to act as a level for the sniper as he aims

The telescope is out of the bracket at the moment. I made a small rest some time ago as you explained in one of your articles for centering the telescope ( I did these for my MkI telescope). In these rest I can level the crosswire to my wallchart that I use for classroom boresighting.
As I look trough the telescope I have the impression that the crosswire and post are square. When I level the crosswire horizontaly it does not appear to be parallel with the range or square to the deflection drum.

Hello Peter,
for testing my telescopes I like to ask about the size of the Chart, testing No32 Telescopeas shown on page 95 of your book. Is it really full size as the text says?

FrankLE: I believe the illustration in Mr. Laidlers book is a reproduction of an original chart shrunk down to fit the page size in the book. I have two separate Canadian Army books that have virtually the same diagram but 153% larger. Assuming the charts I have are correct dimensionally you can use a good expanding photocopier to enlarge the chart by the factor indicated. I believe the charts I have are of original size as my Chinese repro No.32 Mk1 matches the ranging on the chart perfectly- have yet to try my real No.32 Mk3 on it.

Ridolpho

The easy way to tell is the situation is acceptable is to return the scope to the rifle, place it in a cradle, level the crosswire, lock the rifle in place as best you can and then see how the elevation adjustments track againt a vertical reference at some arbitrary distance. If the tip of the graticule stays on line with the vertical reference, then nothing else matters.

I used a yellow engineers string and plumb weight at 25' and a small level on the receiver and range drum to compare. But that was back in the stone age 90's while waiting for Peter's book. I'm sure you all can do better. On the square and on the level.

..MJ..

Thanks everybody for the help.

I tried today with the telescope mounted into the bracket and to the rifle. Clamped the rifle into a vice and leveled it horizontaly. The crosswire levels exactly horizontal and the post runs up and down exact vertical. Used a string and plumb weight to control.
But the top of the range drum is not parallel to the crosswire. The deflection drum is square to the leveled rifle.

Even with the top surface where the range drum sits on is not parallel it works correct and thats the most important thing.

I have another question about my L42A1. The rifle came with a wrong rear sight. There was a No8 rear sight with battle sight removed on it.
I am now looking for the correct sight Mk1 converted to meters and marked with M.
Knowing that they are very rare, is there any chance for getting hold of one???

It is SIMPLE to modify a sight Frank. Get a Mk1 sight and strip it down. Clean it while it is apart and then carefully file off the cursor line from the slide. Now carefully stamp a new line .70" LOWER down than the original line across both sides of the slide. Then engrave or stamp the letter M onto the left side of the slide.

It is only the slide part that was modified. The remainder oif the sight was bog standard No4T

Sorry for German but ...

Frank, ich glaub ich hab noch eines oder zwei von den Mikrometervisieren daheim rumliegen die ich mal von Numrich um 35€/Stk. importiert habe. Falls du keines haben solltest, kann ich es zur Börse nach Breitenfurt Anfang Februar mitbringen, schick mir ggf. eine PN.

Quote:

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Originally Posted by Frank LE

Thanks everybody for the help.

I tried today with the telescope mounted into the bracket and to the rifle. Clamped the rifle into a vice and leveled it horizontaly. The crosswire levels exactly horizontal and the post runs up and down exact vertical. Used a string and plumb weight to control.
But the top of the range drum is not parallel to the crosswire. The deflection drum is square to the leveled rifle.

Even with the top surface where the range drum sits on is not parallel it works correct and thats the most important thing.

I have another question about my L42A1. The rifle came with a wrong rear sight. There was a No8 rear sight with battle sight removed on it.
I am now looking for the correct sight Mk1 converted to meters and marked with M.
Knowing that they are very rare, is there any chance for getting hold of one???

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Sounds to me like someone has cross-threaded the knurled portion of the drum onto the "core" or "shank" - whatever one wants to call it. Is there a fine grub screw present where the two join?

I've got some of those modified slides here somewhere, if you need one.

https://www.milsurps.com/images/impo...standard-2.jpg