Dents in case mouth after firing

I recently purchased an old 1973 Colt 1911 from a retired bullseye shooter.  It was set up to be an iron-sight wad gun, but I bought it to use as a Service Pistol (the relaxed ammo rules for Service Pistol are helping me).  I shot it for the first time a couple days ago.  It shoots pretty well, and had no failures through 100 shots (I need practice with iron sights, though).  However, I noticed that about 1 or 2 out of every 10 fired cases has a dent or indentation on the case mouth. The other 80%-90% seemed fine.  See attached photos (note that close up of the brass looks pretty beat up, because it is... this is Starline brass on it's 14th firing, and it still shoots great at 25yds).

Any idea what's causing this?  

If it matters, the gun ejects the cases almost straight up about 60% of the time, but the direction of ejection is pretty random overall (which I need to fix, because a couple came back and hit me in the face (directly, not just on the downward arc), which is more than slightly distracting in sustained fire).

Thanks,
Dave

Maybe check extractor tension

Fix the ejection pattern first.  That might take care of the denting issue.

And see if your ejection port was lowered.  This photo shows the difference.  The 1911 has a slide bottom to port distance of .6 inches and the Gold Cup is .5 inches.  

Wobbley wrote:Fix the ejection pattern first.  That might take care of the denting issue.

And see if your ejection port was lowered.  This photo shows the difference.  The 1911 has a slide bottom to port distance of .6 inches and the Gold Cup is .5 inches.

The Colt ejection port is 5/8" above the bottom of the slide.  So, not lowered.  I'm hoping that, even with the high ejection port, I can still get them to go mostly to the right.  Is that reasonable?  Or do the ones with the high ejection ports always eject straight up?

I haven't taken the Colt apart yet, but the ejector is very different than the one on my Springfield Range Officer.  On the RO, the tip of the ejector sticks forward and is actually angled down (with the bottom corner filed back), but on the Colt it's more of a blade shape with the top corner filed back. 

I know the basic idea is to gently re-shape the front of the ejector to change the angle of case ejection, but if anyone who has done it before has any suggestions, I'm all ears.

Thanks,
Dave

james r chapman wrote:Maybe check extractor tension

I would check this and make sure the extractor is actually hanging onto the case.  I had a hardball gun that used to put black half circles on my forehead because the extractor couldn't make it to the case.  You could slide a case up and down through the area without any grasp, no matter how much tension there was.  The fix was to remove a little of the inside area of the extractor right behind the hook opening, so it could reach the case.