The most common and most likely answer to this crossword clue is the 10 letter word PARADIDDLE
I've seen this crossword clue in Financial Times
P
A
R
A
D
I
D
D
L
E
More clues leading to the result PARADIDDLE
Buddy explains!

The straight part
We know that "series of hits" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case series of hits = paradiddle.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 PARADIDDLE mean?
PARADIDDLE noun- A percussive exercise (one of 26 drum rudiments) which involves playing four even strokes in the order ‘right left right right’ or ‘left right left left’
- To produce percussive sounds of this kind.