I spent 2 yrs on the A.R.C. lake(mallard) and only ever caught 2 bream although they were 14lbs plus.They are very difficult to track down i spent time with some excellent bream anglers targeting these fish and suffered endless blanks its not for the faint hearted.
Bluebell lake is a better bet if you after a double but the shoals are massive and can eat a mountain of bait the average is about 7lbs.
We used to fish pegs 1 to 5 on bluebell and once they were on the bait take up to 15 fish a day on groundbait feeders and yellow plastic corn