After playing with the gun outside, having a ball (5,3)

I believe the answer is:

great fun

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'ball' is the definition.
(thesaurus)

'after playing with the gun' is the wordplay.
'playing with' indicates anagramming the letters.
'after' anagrammed with 'gun' gives 'GREAT FUN'.

'outside having a' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.

Can you help me to learn more?

I've seen this clue in the Evening Standard.

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