1) the ping

It may have happened once or twice, but there is no possible way it was a common practice that worked. iv been in quite a few firefights, u are not hearing a ping coming from the enemy. also 99% u are with multiple people pinging all at diffrent times, but fire is still being put down. Its bullshit. Here is another thing no one wants to admit to. Vets Lie or missrember. They will addopt stories they hear from other people as their own. Iv served just shy of 20 years, and have deployments, iv seen it, and im sure i probly exaggerated myself or missrembered events.

2) Magazine vs Clip
i will take a magazine any day over a clip. even if its same amount of ammo. its faster to reload and more ergonomic to do so. It also allows u to change out mags to top off during a low in the fight at anytime.

the military back then and before had a mind set of "we dont want our guys to waist ammo" well suppressive fire is not wasting ammo. and is vital to modern tactics. more rounds shot, more the enemy is fixed and more of a chance they will be hit. One shot one kill is unrealistic, dangerous mindset and ineffective for infantry in a firefight.