Used real tin out of military convenience (7)

I believe the answer is:

latrine

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'military convenience' is the definition.
'latrine' can be an answer for 'convenience' (latrine is a kind of convenience). I'm not certain of the 'military' bit.

'used real tin' is the wordplay.
'used' is an anagram indicator.
'real'+'tin'='realtin'
'realtin' with letters rearranged gives 'LATRINE'.

'out of' acts as a link.

Can you help me to learn more?

(Other definitions for latrine that I've seen before include "Toilet in a military area" , "where to go in the army" , "waste disposal unit" , "Camp lavatory" , "Army lavatory" .)

I've seen this clue in The Daily Express.

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