The most common and most likely answer to this crossword clue is the 5 letter word ESSES
E
S
S
E
S
Buddy explains!

The straight part
We know that "what’s found at beginning and end of sorties" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case what’s found at beginning and end of sorties = esses.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 ESSES mean?
ESSES noun- The name of the Latin-script letter S.
- Something shaped like the letter S.
- To move in a changing direction, forming the shape of a letter S.
- (usually plural) A sequence of winding turns.