Global Reported Arms Trade.
provides free access to information about the transfer of arms, imports and exports, using data recorded in the UN Register of Conventional Arms. Since its inception in 1991 the register has recorded data relating to 170 states. Note that this only records transfers between UN Member States Categories include small and conventional arms, military expenditure.
It is possible to view reports by type of weapon and nation from approximately 1992 onwards. Statistics are being added to the site on a rolling basis not all are yet complete. On this topic other useful databases are provided by Stockholm Institute. They also cover military expenditure and arms transfers

From LSE library blog