Like guns that shoot every time? (8)
I believe the answer is:
surefire
'every time?' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'like guns that shoot' is the wordplay.
'like guns' becomes 'sure' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'that shoot' becomes 'fire' (as in firing a gun).
'sure'+'fire'='SUREFIRE'
Can you help me to learn more?
(Other definitions for surefire that I've seen before include "certain to succeed" , "Always effective" .)