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_26967904_2 (a_external__cm_2__ VARCHAR, chambering VARCHAR)
### Question:
How many  external (cm 2 ) are there for the .338 lapua magnum chambering?
### Answer:
SELECT COUNT(a_external__cm_2__) FROM table_26967904_2 WHERE chambering = ".338 Lapua Magnum"