Welcome to the forum,,,,now the test is that YOU must assume gunsmith position Number 2, on your hands and knees and back track the direction the gun was pointed, you lost it, you find it, unless you were outdoors or in a boat out on open water, you will find it...Good luck:cool:
...and yes most cases the recoil spring plugs are the same, mil specs interchange..;)
...and in the future, many of those you will see/find, a divot ( dimple) on the inside up near the front end, this is to actually "hook onto and catch" the open coil end of the spring and hold it ON ,,,,,,,,,:rolleyes: