Question for Tuner

[ken grant]

what causes brass marks on the top of the slide in front of the ejection port?
They run from about 12 o'clock to 1` o'clock on the top. 1/4 to 1/2 inch from the front of the port

 

[1911Tuner]

Marked Slide

Brass not getting clear of the port in time to get out of the way of the slide.
Slide smacks it and bats it backward...sometimes right in your face...sometimes over your head. A lighter recoil spring may help....or not.
A little shorter ejector may help...or not. Sometimes these things are trial and error. Try undercutting the bottom side of the ejector at a shallow angle to raise the point of impact on the case rim to cause it to kick out of the port at a lower angle.