What sighting telescope was fitted to the 17 Pounder M10 that equipped some RA Anti tank batteries

I am trying to find out what Telescope Sighting was fitted to the 17 Pounder M10 SP in 1944-45.

RA Notes No 14 from early 1944, Para 799 headed 17 Pounder SP M10. dated from early 1944, describes the successfull converrsion, fitting a 17 Pounder Mk II into the cradle. There are six sub paras detailing the modifications, including boring out the cradle by 2/10" to fit the 17 pounder, adding a muzzlebrake and counter weight. There is no mention of the sighting telescope.

Para 800 lists modifications to the 3" GMC M10 applied as a result of (British) user experience, and a comment that many ofmthese changes are also applicable to the 17 pounder M10 SP. The first two points listed are:-

i Filling a British Dial sight and sight clinometer (which is to the right of the gun in the 3 inch GMC)
ii A new sight bracket for the No 51 sight (illuminated) with an open sight.

There is a thread on the Historic military history forum which claims that the sight is a Mk 43 - as per the Sherman c (Firefly)
17 pdr gun sight

Now the No51 Sight reticule is simply a set of cross hairs with graticule for adjustments for line. .


While the Telescope sighting No 43 ML Mk 3/1 has range graticules for HE APC and APCBC rounds. This is from a 1945 manual on Tank telescope in the Bovington archives
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As you can see if has a range graticule for a co-ax MG and HE - which looks like the sight for a Sherman Firefly. Looking at sighting telescopes offered for sale there is another version of the Mk 43

This would make more sense for a 17 pounder M10 SP.

The HMVF forum mentioned that the RA and RAC had a different approach to sighting. The RAC set the sights using graticules in the telescope, while the RA applied a range using a range drum fixed to the sight bracket ..




This sounds sensible, but I can't seem to find photos of a range drum attached to the 17 pounder in the M10. It can't use the same sight bracket as the towed gun. Surviving examples have a telescope in the turret front. Am I missing something?

Any viewes on which is the correct telescope and graticules?

 

Looking for technical data for you……for the TM for the M10 3” just for interest purposes

https://ia800502.us.archive.org/12/items/TM9-731G/TM9-731G.pdf

TM 9-752 3-Inch Gun Motor Carriage M10, 1943 : United States. War Department : Free Download, Borrow, and Streaming : Internet Archive

 

Found this on Heritage Canadiana. If you go to the link I’ve supplied below, it list pages and pages of British equipment and the sights that various tanks/gun etc could be equipped with (if you want all the pages for future reference)




Link: War diaries : T-12746 - Héritage


The various US supplied sights (M51 & M70C) at the link below

#64 Sherman Fire Control: How the Gun Was Aimed, not Putting Out Fires! | The Sherman Tank Site

 

I thought I may as well post all the sheets on this subject, in case others are looking for like information on other equipment









Source: War diaries : T-12746 - Héritage

 

Thanks chaps! Confirmed that its the Telescope Sighting No51 - so there must be a range drum on the 17 Pounder Mk II installed in the M10

 

This is info for the towed gun...

Incidentally we need to distinguish between the sight and the telescope. It seems the range drum was a component of the sight, and the telescope was mounted in the sight. The "No 43... Mk 3 and 3/1" would be a Mk 3 or 3/1 sight, with the No 43 telescope installed, I think.








(So I can now relate the diagram and your photograph of the towed gun)

Somehow when I looked at this earlier in the month I did not quite understand it all. Now it is crystal clear!

PS I don't think the 5/1 was installed until after the war. You have probably come across range equivalences being calculated in summer of 1944 for the use of DS ammunition? If not I have a reference.

 

This is what is said about the M10 17 pr at the end of the book.

 

The post war armament pamphlet specifies the No 43 sight. Whilst the No 51 does require a sight mount with a range drum, this does not preclude using the No 43 sight, you would just have to be careful not to adjust the sight and that also assumes it's a No 43 x 3 ML. The M denotes Moving graticule. Most sights were available as a x1.9 fixed graticule, though the lower magnification would be detrimental in this case.

 

Hi tanjbarrell, which booklet do you mean? The equipment would have been different after the RAC took over anti tank duties in 1950. But possibly you mean earlier than that?

 

Hi Chris, not it is 1952 and part of RAC equipment. That might be the reason for the change, that hadn't occurred to me! Perhaps the change was made simply because it was a better sight and was already part of RAC equipment.

 

RA M10 17 pounder SP's were fitted with the 1.9x No.41 Sight, as I posted previously here.

There was much resentment that the RA sights were inferior to the RAC's.

 

The RAC changed the telescope when they took over the Archer (at the same time), fwiw. And yes, I think both better and part of RAC equipment. I believe it could be switched between x3 and x6 magnification.