Ed the paint is Rustoleum Camo paint in tan, light green and earth brown. Pattern was made by using a natural sponge. The sponge can be found in the craft section in Walmart in a mesh bag with about 6 pieces. Here are the steps the way I did it (following a video by another person on YouTube):
Remove the stock and any hardware you don't want painted and remove all oil and grease. You can use 91% alcohol or a gun scrubber (if using the latter check an inconspicuous area to make sur it doesn't damage the stock)
Lightly sand the entire stock where you're going to paint to roughen it up. Mask any areas you don't want painted.
Spray the entire surface with the light brown/tan paint. Use light coats and do not over spray or you will get a frosted appearance (read the directions on the can). Hang and let dry.
Next take the earth brown paint and spray onto a piece of cardboard to form a puddle. Then take a piece of the natural sponge and dip it lightly into the puddle. Dab the cardboard until you find a pattern you like from the sponge. Start dabbing the stock however you like. I prefer a random pattern as it appears more natural. Don't worry about doing too much. You can always cover it up with the green.
Once the brown is dry you can do the same thing with the green.
Give the stock and entire day to dry then spray it with some clear matte finish polyurethane. As many coats as you prefer.
Note: This camo will give the stock a rough, almost sandpaper like, feel. At least mine did.