Why aren't you guys just chambering a round by racking the slide? Then top off the magazine.
When the round hits the feed ramp as it is chambering it causes the bullet to setback in the case which can cause unsafe pressure spikes. Sometimes all it takes is one or two chamberings to notice a difference. Since my pistol is a blowback design where the feed ramp doesn't tilt back like a glock or similar design, along with a heavy recoil spring slamming that slide forward i'm guessing is the reason it's happening so quickly. So I figure instead of ruining $1 per round ammunition, when I chamber my gun with my carry rounds manually loading the first cartridge into the chamber prevents the bullet setback.