Another thing to look at, would be to make sure that the Recoil spring is not too long. If the spring is bottoming out prior to the slide not fulling comming back, it may cause the weak extraction. Check the Slide's range of motion with and without the recoil spring installed. I just went through a similar problem and found my brass was getting bad. If you don't have an EGW Undersized Die, get one. It will help with any extra bulging. Unfortunately they have a 2 month backorder currently. I'm waiting for one for my 40.
Good Luck
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