There are potentially coin finds out there that will be different weights due to a few different reasons which can be worth a premium you can read about here so coin roll hunters may do well to weigh their coins and become familiar with whats normal.
https://varietyerrors.com/wrong-pla...price-guide/ but generally the weight difference is just from normal tolerance differences as yours appears to be within the normal tolerance as mentioned already by others and these will not carry any premium. Regarding 2.7g, While 1943 super rare copper cents weigh about 3.11 grams and don't stick to a magnet, the more common 1943 normal steel cents (which weigh 2.7 grams not taking into account tolerance) adhere to a magnet.
