From Longman Dictionary of Contemporary Englishramrodram‧rod /ˈræmrɒd $ -rɑːd/ noun [countable] 1 → straight/stiff as a ramrod2 PMWa stick for cleaning a gun or pushing gunpowder into an old-fashioned gun
Examples from the Corpus
ramrod• Said he was as stiff as a ramrod and would get nowhere, but he's pretty hard on people anyway.• Straight as a ramrod, Herbie marched to the bar.• Connerly became the ramrod on anti-affirmative action legislation.• He slid the ramrod out, jammed it down the long barrel, then pulled it free.• It was her father she looked for, and there he was, ramrod straight, a head above the rest.• They were scared men, even Schiller was ramrod straight in his seat. 