The most common and most likely answer to this crossword clue is the 8 letter word RUMMAGES
R
U
M
M
A
G
E
S
Buddy explains!

The straight part
We know that "rifles" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case rifles = rummages.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 RUMMAGES mean?
RUMMAGES noun- A thorough search, usually resulting in disorder.
- Commotion; disturbance.
- A disorganized collection of miscellaneous objects; a jumble.
- A place or room for the stowage of cargo in a ship.
- The act of stowing cargo; the pulling and moving about of packages incident to close stowage.
- To arrange (cargo, goods, etc.) in the hold of a ship; to move or rearrange such goods.
- To search a vessel for smuggled goods.
- To search something thoroughly and with disregard for the way in which things were arranged.