This Bible contradiction is from the Skeptic's Annotated Bible.
1 Samuel 7:1-2 View context
And the men of Kirjath-jearim came, and fetched up the ark of the LORD, and brought it into the house of Abinadab in the hill, and sanctified Eleazar his son to keep the ark of the LORD.
And it came to pass, while the ark abode in Kirjath-jearim, that the time was long; for it was twenty years: and all the house of Israel lamented after the LORD.
1 Samuel 10:24 View context
And Samuel said to all the people, See ye him whom the LORD hath chosen, that [there is] none like him among all the people? And all the people shouted, and said, God save the king.
More than forty years.
2 Samuel 6:2-3 View context
And David arose, and went with all the people that [were] with him from Baale of Judah, to bring up from thence the ark of God, whose name is called by the name of the LORD of hosts that dwelleth [between] the cherubims.
And they set the ark of God upon a new cart, and brought it out of the house of Abinadab that [was] in Gibeah: and Uzzah and Ahio, the sons of Abinadab, drave the new cart.
Acts.13:21 View context
And afterward they desired a king: and God gave unto them Saul the son of Cis, a man of the tribe of Benjamin, by the space of forty years.