Trying to id what type of thing would this sent flying (Artillery Caseing?)

Factual Questions
1

Could someone identify a ww2 era shell caseing for me please

2

Is it a 5-inch?

3

I think its a 155 mm long tom shell.

Declan

4

Too narrow. More like a 105mm. The 155mm uses bagged increments, not cased rounds.