Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_16439764_1 (shell__lb_ VARCHAR, gun VARCHAR)
### Question:
If the gun used is the qf 12 pdr 12 cwt, what is the shell weight?
### Answer:
SELECT shell__lb_ FROM table_16439764_1 WHERE gun = "QF 12 pdr 12 cwt"