Last year I bought a small farm (pine trees & pecans) in North West Florida. On the place I have two ponds, a new dug pond and an old 1929 vintage dam made pond of about 1 1/2 acres. Well the new pond has nothing in it except water and not much of that, until I get the pond liner folks out in about two weeks.

The price of several nice guns we will get that fixed, which is a long story involving a contractor that went out of business.
The old pond is full of stocked fish and the turtles are like a blight, just everwhere. Sunday in about 10 minutes, just after noon, I shot 3, from a standing position with my 512 Remington and a couple weeks ago shot 5 with my Browning Buckmark Target. Turtles with a 22LR are quite a challenge, especially the head only buggers at 100 plus yards.
One word of caution, always shoot to a solid backstop when shooting turtles off of a pond. 98% of the bullets do not stay in the pond. I am very lucky as the old pond is in a depression and shooting from the shore allows the other shore to be the needed solid backstop. Also being a tree farm, I have a 1/4 mile of big pine trees around the pond, so if the bank does not stop the bullet, a tree will. Think safety before you shoot.
I also use my 218 Bee as my turtle gun and it has the added accuracy and range needed for the longer shots.
Best,
Ed