Rifle shots make two noises if you are being shot at. The first is the sonic boom or “crack” you hear as the bullet passes. The second is the “report” you hear from the firing of the bullet.
Pistols don’t typically shoot a supersonic round so you won’t hear a “crack” as the bullet passes.
Thanks Gravity, the 2 types of rounds that I 100% can identify what they were and they were flying about 6 feet over my head were volumes of 5.56mm NATO rounds which travel at about 3200fps and the 7.62 NATO rounds which travel at 2500-2700fps. Sonic velocities are roughly 343 m/s, 1,125 ft/s, 768 mph, 667 knots, or 1,235 km/h. I'm guessing those are STP stats.
That "crack" is what I heard as I was "in the butts" at the CF rifle range lowering, marking and raising targets while the others were firing at the targets. When behind or at a distance, the "report" is all I could hear.
You are right about the pistol velocities. A suppressor will quieten the "report" of a weapon, it does nothing to muffle the "shock wave" of a supersonic bullet.
Just think the Space Shuttle would travel at 17,500mph or about 25,000fps. The SR-71 moved at 2200+mph or 3200fps, literally faster than many speeding bullets.
STS sonic booms, especially for you Gravity!
https://www.youtube.com/watch?v=lNL4HHFG8H4peace
Hog