The 1929 and the 1936 Arab riots converted him to activism, and in 1937, while still on police service, he joined the Irgun.
As a policeman, he succeeded in conveying important information to the underground and thus found his way to Delek, the Irgun's intelligence service.
In 1945, after the Haganah kidnapped Tavin, Amrami was appointed commander of Delek, and later became a member of the General Headquarters.
In 1947 he was severely beaten by Haganah people and required medical treatment. After recovery, he was sent to Europe to deal with purchase of weapons and their dispatch to Eretz Israel. He returned after the establishment of the state of Israel.
He set up the Hadar publishing house, which mainly published books connected with the anti-British underground.
Wrote a book entitled 'Hadvarim Gdolim Hem Me-itanu" (Hadar, 1994).