[HiBC]

What kind of ammo are you using?

You might try a sample of plain,common brass case 9mm hardball,like the white box or Fiocchi or WW.

A 9mm chamber is not real difficult to inspect.Pull the barrel out,grt under good light,and look at it.A 10x or less loupe will look down in there.

A mechanical pencil,with the thin lead,you can drag and probe around in there,you will be able to feel any significant texture.It you can't feel the flaws with a pencil tip,probably insignificant.Silly putty does a great job of taking an impression.A gob pressed onto the chamber wall and carefully lifted off will give you something to read.Did you look at the brass?Anything strange?Gall,scrape,scratches,etc?

This is pretty much like a 1911,right?You may have what Khunhausen would call a timing issue.

How things are hand cycling is not necessarily how they are in the dynamics of firing.
Unloaded,hammer cocked,put your thumb in the guard and finger under the bushing and ease the slide back about 1/2 in.The link will pull the barrel down,you will feel the underlug of the barrel contact the frame.That is where the barrel stops.The slide continues back on its own....unless the barrel DURING THE DYNAMICS OF FIRING has not been linked down enough to fully disengage the locking lugs,with some clearance.Due to the geometry,its the forward lug that is least likely to fully disengage.

This condition is quite likely to cause damage to the locking lugs of the barrel and or the slide.Inspect the locking lugs for signs of upset or battering

Back to the test of easing the slide back to full linkdown ,barrel underlug just contacting frame,they used to sell a little kit,a srpring to force the barrel up,and a piece of narrow feeler gage,I don't remember the thickness,but lets guess .012 for nowWith that spring forcing the barrel up into the locking lugs,the feeler gage needs to slip freely between the barrel and the slide,ahead of the ejection port,assuring there is clearance between the barrel and the slide at linkdown.