Looking at Bibb Co, GA (county seat is Macon), there are two Walter BARTLETTs in my files - one born there in 1884, and one in 1886 - to two different families (Walter may have been a popular given name at the time). One of these two could have been the namesake of your Walter b 1942. One of these two Walters is from a line for which we have the Y-DNA signature; the other is from a line we do not know the Y-DNA (Legrand BARTLETT b 1830 SC...)
Again, the best bet for narrowing down your search is to take the Y-DNA37 test.
Do you have any record that states where Walter was born?