Constantly Rejected Wheat Pennies?

[JohnDN90]

I have a CC-16D CMI#66160081 Coin Comparitor, with the inhibit function. I sorted 200 pennies with it. It only rejected 1 copper and 1 wheat penny. So I turned the potentiometer until it accepted the copper. Then I got handful of wheats and started running them through, and adjusting the potentiometer until it reached full accept side (fully counter clockwise). At the full accept point, the coin comparitor should accept all coins, but it will still kick these wheats out. All of them are the dark oxidized copper look, the only one more visually dirty than normal is the 1919, its pretty rough. Does anyone have any idea why these won't are constantly rejected? Here is the list.

Year Weight
1919 3.17
1935 3.11
1940 3.01
1940 3.06
1941 2.99
1941 3.05
1941 3.11
1941 3.11
1941 3.07
1944 3.06