The most common and most likely answer to this crossword clue is the 8 letter word DISARMER
I've seen this crossword clue in The Guardian
D
I
S
A
R
M
E
R
More clues leading to the result DISARMER
Buddy explains!

The straight part
We know that "he might have removed guns" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case he might have removed guns = disarmer.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DISARMER mean?
DISARMER noun- A proponent of disarmament.