can u id these recent forshore finds???

[thehoods]

these are recent forshore finds near a ww2 british merchant navy gun site.....anyone know what they are from/for???
first one is a small jam jar size metal object with heavy stamp marks on top from 1941. these pretty much littered the the area.

This is very heavy and is dated 1942 with a broad arrow and 1.75 along with several other markings. i have a basic understanding of what this could be but really need full details.

hope u can help identify??

 

[Nismosonic]

Look like they could possibly be fuze plugs... (fitted to shell instead of fuze after shell is loaded. Fuze would then be fitted at a latter time, possibly just before use of shell)

 

[Chris 42 RQ]

What diameter is the second item as it looks a bit like the top of either a 3 inch or perhaps a 2 inch rocket motor with the eight fixing studs they use.

 

[thehoods]

about 2 half - 3 inchs

 

[Chris 42 RQ]

3 inches would make it the top part of the rocket motor which secures to the payload/warhead/projectile.
The round things are small studs that are held in place by an internal sprung ring which keeps them pushed outwards-so inside you would find two rings made from a spring material and eight or more shouldered "buttons" that are retained by the spring rings.
Quiet why it would have ablind plug in the top I do not know unless the motor has been "destroyed" having been surplus/out of date or damaged for some reason.