Gun heads, what reasons would cause a gun to squib load?

All of a sudden my unfired gun is squib loading and I don't know where to even begin to fix the issue, is it the rounds? I will admit that everytime I come home, I unchamber the round in the barrel, so it might be wear to the rounds but the gun slides smoothly but about every 8 rounds it jams into a squib round, the gun hasn't been fired, it hasn't been half a year since it was cleaned and lubed, is it a faulty mag spring?

How I realized it's jamming was when I tried to unchamber it, the first round jammed so I did racking tests by cycling full mags through it and i did it 4 times, used the same mag twice and it jammed both times on that mag, I used another twice and it didn't jam, at this point I don't know if its the gun, mag or rounds 😐
Gun heads, what reasons would cause a gun to squib load?
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