Leftists deliberately fudge up gun stats, because they want experts to correct them. Why? Because, they want to point the finger at the gun expert who actually knows the specifics about muzzle velocity and other intricate details about guns. They want to show their supporters how ridiculous it is that any average citizen would know this information in the first place and that these type of gun nuts are dangerous people.
I’ve been reloading my ammo since the 60’s. 223 factory loads are around 3000 fps. Changing powder loads or types you can improve the velocity. Pistol ammo is typically under 2000 fps. Some pistols are made for rifle ammo, but velocities are limited because of the short barrel lengths (the powder doesn’t burn completely)
I double loaded a 218 Bee round and fired it in my Thompson Center Contender pistol once. Rookie mistake, Lee Loader. Had a very difficult time extracting the case. Lots of smoke. Lee Loaders were my first experience at reloading in 1968.
Respectfully, I believe you’re over thinking it.
They say it because one, someone told them to say it, and their just too stupid and ignorant about guns to know better. Also, they want to make guns sound as scary as possible, and they know their audience is also stupid and ignorant about guns in general, and further, they know that they will not be called out on it in any significant way that will get through to the ignorant.