July 1, 2011:
Four years ago, Canada donated 2,500 C-7 assault rifles to the Afghan Army. The C-7s are variants of the U.S. M-16. Recently, the Afghans returned the gift. Most of it, as hundreds of the donated C-7s had been lost (to battle, theft or whatever). The problem here was that the Afghans had subsequently decided to standardize on the M-16, and the C-7 is just different enough (and has several parts that are not interchangeable with the M-16) to be unsuitable.
On the plus side, the 2,500 C-7s were due to be destroyed anyway (they had been in service since the 1980s), and the gift came with training on how to use the C-7s. This was not wasted, as it takes very little time and effort to switch from C-7 to M-16. Canada also included seven million rounds of 5.56mm ammo, which works equally well in the C-7 or M-16.