Cat.S
A pistol calibre bullet will make a hole in the skin, but the effect will be neglible, even at max diff. To do any real damage to aircraft structures you need 23mm as a minimimum, and that includes an HE component. As for component damage, highly unlikely, aircraft are not dense structures and systems have a high degree of redundancy.
The MoD supplied my ammunition, I would have thought that it was obvious by my use of "PPW"
RAGBAG