From Charles Poliquin's website:
"What is considered a good result in the front squat? I?ve read that top super heavyweight weightlifters such as Paul Anderson, Vladimir Marchuk, Alexander Kurlovich and Mark Henry front squatted at least 317.5 kilos (700 pounds!), and absolute clean and jerk world record holder Leonid Taranenko did 300 kilos for 3 reps.
Two other weightlifters who deserve mention are three-time Olympic champion Pyrros Dimas of Greece and Dursun Sevinc of Turkey; both weighed 85 kilos (187 pounds) and lifted more than 272 kilos (600 pounds) in the front squat. The all-time record appears to be Warrick Brant, who did 350 kilos using the technique with the arms crossed in front ? you can see a video of him doing 340 kilos on YouTube."
"Q. What is the ratio between the front squat and the back squat?
A. If you are going all the way down in both exercises, generally the ratio of front squat to back squat is about 85 percent. So if you can back squat 100 kilos, you should be able to front squat 85 kilos. One reason few athletes achieve this ratio is that they do not back squat all the way down, thus inflating the amount they can actually lift in this exercise."