the laser sprite is 1060 pixels wide? oh my
do you draw a line on it? then draw the sprite on the sheet?
there are multiple ways to solve this problem, such as just drawing a line from (tankX, tankY) to (objectX, objectY)
the line would be red with some LineWidth = 4.f; or so, if you are using .NET
EDIT: oh right, SFML and c++, i have never used SFML before.. so i can't help you there
but, can't you just draw a line? from A to B..
Depending on how far you want to go, lasers can be complex effects
In the old days, you could combine many small sprites that formed a line, and i'm sure you can do that today too with some alpha+shader magic
Not sure what your options are with SFML though.. sorry