Ruger PC Carbine Chamber Question

[albayo]

I shot a Ruger PC carbine the other day, and one side of the brass is black.
I looked in the chamber and it looks like the lower part of the chamber is cut deeper than the top.
Is this normal or part of the design?
If you look at the part of the chamber where the 9mm casing stops when the round is fully seated the ring isn't uniform.
The ring is wider at bottom than the top. That in my opinion is why the casings that are ejected and are dark on one side.
What do you think?

 

[B]

It's a blowback gun black cases are normal. You are looking at the cutout that the feedramp leads into unless I am misunderstanding.

 

[Ribstaylor]

The recoil spring is from what I gather to weak for this rifle out of the factory. Mine and many others can barely even make the bolt hold open keep open, any movement or wait shift causes it to close. I've also seen others who instead of a #### hold open, get black casings because the spring isn't strong enough to hold the casing in place for long enough for the powder to fully burn up. A stronger spring from a company called MCarbo should fix this both your issue and mine, they just can't ship to Canada till next year do to international licensing or some ####.


Edit with link (There is a pic in the product page that shows the change in case dirtiness)

https://www.mcarbo.com/ruger-pc-carbine-extra-power-recoil-spring.aspx

 

[albayo]

Feed ramp is not the problem it's as if the chamber doesn't appear to be completely round.
A friend of mine is going to get a bore camera and some measuring instruments to check it out.

 

[B]

Feed ramp is not the problem it's as if the chamber doesn't appear to be completely round.
A friend of mine is going to get a bore camera and some measuring instruments to check it out.

Some pictures would help. I was trying to wrap my head around your post after a long night shift.

 

[Gatehouse]

Lots of PCC's leave cases blackened. By all means check it out, but I bet it's nothing to worry about.