### Clue: Scrapes the barrel, recruiting bottom of the pile into forces (5)
### Answer: REAMS 
 ### Explanation: Definition: Scrapes the barrel
 **The last letter of**(bottom, in a down clue) pile **contained in**(into) RAMS(forces;pushes through).
Answer: Removes;scrapes material from inside a barrel, eg. of a gun or cannon, in order to increase the bore, with a reamer, a scraper-like tool for that purpose.