Mortgage rates hit rock-bottom this week following a key cut in the federal funds target, as the average 30-year fixed-rate mortgage sat at 5.19 percent — the lowest rate ever recorded by Freddie Mac (FRE), who began tracking rates in 1971 — with an average 0.7 point.  That’s down from last week’s 5.47 percent average, and far below the average of 6.14 percent recorded last year at this time, according to Freddie Mac’s weekly survey published Thursday. This week’s five-year treasury-indexed hybrid ARMs averaged 5.6 percent with an average 0.6 point, also down from last week’s 5.82 percent average, Freddie Mac reported. One-year ARMS followed the downward trend, falling from 5.09 percent last week to 4.94 percent with 0.5 point this week. “Interest rates for 30-year fixed-rate mortgage rates fell for the seventh consecutive week, moving these rates to the lowest since the survey began in April 1971,” said Frank Nothaft, Freddie Mac vice president and chief economist.  “The decline was supported by the Federal Reserve announcement on December 16th, when it cut the federal funds target to a record low and stated it stood ready to expand its purchases of mortgage-related assets as conditions warrant.” Bankrate.com’s weekly mortgage rate survey also reported a drop in mortgage rates. The benchmark 30-year fixed-rate, according to Bankrate, fell a monstrous 38 basis points to 5.42 percent. The average 15-year fixed-rate mortgage fell 21 basis points to 5.3 percent. Bankrate’s Holden Lewis said in a report that Wednesday morning, borrowers were snatching conforming mortgages at less than five percent, due to what he calls “volatile Wednesdays.” “In a random quirk, rates have been particularly volatile the last four Wednesdays,” Holden said.  Wedneday happens to be the day when Bankrate conducts its weekly survey, suggesting the survey may not have even captured the depth of this week’s rate decline — a depth that resulted in cases like Wilmington, N.C. resident Glenn Floyd, grabbing a 30-year, fixed-rate mortgage at 4.875 percent, paying only half a discount point. “This week’s survey shows that it pays to shop around,” Bankrate’s mortage analysis said. Write to Kelly Curran at kelly.curran@housingwire.com Disclosure: The author held no relevant investment positions when this story was published. Indirect holdings may exist via mutual fund investments. HW reporters and writers follow a strict disclosure policy, the first in the mortgage trade.