[Lightbulb]

That's what I thought, but I read that it's something to do with the magazines..

Well that's an easy test since its a double action trigger you can take the mag out and pull the trigger.

If that doesn't work try pulling the hammer back and trying again. Now do the same with a mag in with no bb and no gas.

Then with gas.

Then with bb's and gas.

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Oh and DON'T sand anything until you see if it works without the magazine in!

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If it works without the mag its possibly what you read about online, if it doesn't its possibly the trigger spring.