CREATE TABLE table_26967904_2 (a_external__cm_2__ VARCHAR2, chambering VARCHAR2)

How many external (cm 2 ) are there for the .338 lapua magnum chambering?
SELECT COUNT(a_external__cm_2__) FROM table_26967904_2 WHERE chambering = ".338 Lapua Magnum"
SELECT COUNT("a_external__cm_2__") FROM "table_26967904_2" WHERE ".338 Lapua Magnum" = "chambering"