Just sent mine back today for the same issue. I mentioned to CS rep that I had been informed that it could be the mag catch and he told me that it sounded more like a slide stop issue. 2nd time it's happened to me. 1st time I just sent the 7 round mag back and they replaced it. Now both mags are coming out shooting Federal 230gr FMJ. If it doesn't work out this time, I'll probably will be selling it.

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Shield 45