Slide Problem Colt 380

[Dave Waits]

I'm afraid you're going to need a gunsmiths' services on this. As was stated,if you try to file it square you'll move the notch too far back. What needs to be done is a small weld with a TIG on the backside of the notch and then reshaping. At first blush a new slide may seem to be the answer but, remember the slide has to be fitted to both the barrel and the frame. They are not a dropin part. By the time you pay for the fitting, you could be looking at $250-300.00. A smith good with a TIG welder and files can do it for about $100.00.
And afterwards you need to have the slide-release and the slide checked for hardness. The Slide-release should be softer than the slide.

Just thought about this, you need to have the geometry of the slide-release position checked too, it may be out of spec.