Do 1 Kings 9:28 and 2 Chronicles 8:18 contradict?

1 Kings 9:27-28 says:

"And Hiram sent in the navy his servants, shipmen that had knowledge of the sea, with the servants of Solomon. And they came to Ophir, and fetched from thence gold, four hundred and twenty talents, and brought it to king Solomon."

2 Chronicles 8:18 says:

"And Huram sent him by the hands of his servants ships, and servants that had knowledge of the sea; and they went with the servants of Solomon to Ophir, and took thence four hundred and fifty talents of gold, and brought them to king Solomon."

There is no contradiction because Hiram's ships brought gold from Ophir to Solomon on multiple occasions.  1 Kings 10:11 says, "And the navy also of Hiram, that brought gold from Ophir, brought in from Ophir great plenty of almug trees, and precious stones." (see also 2 Chronicles 9:10).  1 Chronicles 29:4 says, "Even three thousand talents of gold, of the gold of Ophir, and seven thousand talents of refined silver, to overlay the walls of the houses withal:"  If each shipload of gold was about 420 to 450 talents, then there must have been about 7 trips from Ophir to make up for the 3000 talents of "the gold of Ophir" used for the temple.