My issue M-14 was made by Springfield Arsenal
I went from M-14(basic) to .45 pistol and machine gun (tanks)then back to M14 (ground to ground radar). I did get to shoot the M16 when I was cadre on a rifle range. I preferred the M14 except having to carry it.
I recall the M-60 had a M-219 coax machinegun, a variant of the Browning M-1919. Eventually they swapped it out for a variation of the Belgian M-240. The only Brownings we had left were the M2 and the M1911.
Then they went to the Beretta M-92 and the M-1911 was considered obsolete.
I liked the M-60A2, except they put the wrong gun on it. A M-60A2 with a 120mm Rheinmetal gun would have been interesting!