Only they are not No4 actions, it is a version of the mauser action. The rifle in it's original .303 form was known as the P14, and dates from 1914 to about 1916. They were built in the USA by several manufacturers, Remington, Winchester, and a manufacturer who usually made sewing machines who's name slips my mind (the ones IIRC usually stamped ERA). The were sent over to help us in our first time of need in the 20th century. My local dealer has a P14 in .303 with the PH target rearsight for the old SRb comp. When the USA then entered the war in 1917 they also needed guns quickly and so they started production again, but in 30-06. They built them instead of the Mauser actioned Springfields as they already had the production lines set up so just had to change the caliber.
In the USA these rifles are generally known as Enfields as the design was from the Enfield factory.
They make quite a reasonable taget rifle in 7.62 as do the Fulton Mauser 98's and most of what you could say about them applies to the P14. At thier best up to 600 yards as they do not compensate like the propper No4 action dose.

Al