I was trained with the H&K G3 with a slide stock. It’s 7.62 and when I tried a 5.56 for the first time (a Swedish AK-5)I literally had to check to see if it did indeed shoot. There was no recoil from the 5.56. Never tried a M-16 apart from checking out the M-4 that the Rangers my squad was seconded to had (I was Norwegian Combat Engineer), no way that can kick to much.
M-4 / M-16 same difference. Unless it’s chambered in something other than 5.56 they all shoot the same. And yeah, it’s nothing like 7.62. As you are aware… you KNOW it when you’re firing 7.62!