Aldis Unit Sight With Aluminium Collar

[Spitace41]

Hi all. Picked this up in the local Cash Converters of all places. I took a punt at £20 and suspect I paid about the right price or maybe a bit too much as these appear to be readily available online. Still, it's a nice looking sight and the optics are in good condition. Just wondering if anyone knows what these were used on as there if very little info on the net. Also, this is the only one I have seen with this aluminium collar fitted. Would anyone care to speculate what this could have been for?

Markings are:

Gun Sighting Telescope Patt. G 344*

Aldis Unit Sight

Aldis Brothers Ltd. Birmingham, No. 181113

Any thoughts would be greatly appreciated. Cheers.

[Spitace41]

Just thought I should add a photo of the reticle. Most online appear to be described as having rings, so I don't know what this denotes if anything.

[paulyelverton]

It slides into the barrel of a gun and is used to bore sight the weapon at an object at a known range say a house or chimney, the weapons sights are then zeroed onto the same object. The gun/ weapon is zeroed to that range. they used to use the same thing on the 30mm on board using the masts at portsdown hill.

[paulyelverton]

I think the aluminium collar stops it from sliding to far down, what diameter Is it?

[Spitace41]

Thanks for the interest. I don't have it on me right now but I would guess it is about 3inches in diameter? Cheers.