Hey I have a question I know you can answer. Watching a few videos then running a magazine through my pistol why is the first round noisier than the rest. Even the guy in the video mentioned this testing different brands of ammo.
Hah!
Not often I get a question I can actually answer. Without going all geeky basically with first shot you are simply pushing out the “squatters” gas. When your can is not in use, like most everything else it abhors a vacuum. While sitting idle it gradually fills up with ambient air, both temp wise and pressure and is happy being equal to its environment. Your first shot is now pushing out the room temp, low pressure gas with hot, high pressure gas. unless you wait a long time prior to taking your second shot you simply do not allow the can to cool and equalize back to the environment. Think icing down the manifold!