Scorched 30 Carbine brass

[BlackJackJoe]

I've shot many rounds downrange over 40 years and a lot of different cartridges. But my .30 Carbine brass seems more scorched from the burning powder than brass from my other guns.
One gun I don't have any experience with is the M1 Carbine. I just got one this year and it has a Rock-Ola barrel, op rod and receiver and the bore is beautiful! Like it's hardly been shot. Is it still possible for the chamber tolerances to be a bit large (allowing too much gas to escape into the chamber)? Or is this scorching a common trait with Carbine brass?
The gun groups fine @ 100yds and functions just fine with no signs of excessive pressure. (I was using good quality factory ammo.)
Any insights would be appreciated.
thanks

 

[rcmodel]

Probably nothing to worry about.

It can be a result of:
* hard brass not expanding soon enough to get a good seal.
* low pressure load not expanding the case fast or tight enough.
* dirty burning powder.
* or a semi-auto action starting to open while there is still enough residual chamber pressure to blow soot and crud back alongside the tapered case seal.

I'd try another brand of ammo before doing anything else.

Anywho, if it's not blowing fire & brimstone in your face each shot, it is nothing to worry about.

rc

 

[Cherokee]

I've shot lots of 30 Carbine, usually the fired brass is clean but sometimes its a little dirty. No concern if no pressure signs.

 

[Sunray]

My near max handload toasts the brass a bit too. Nothing to worry about.

 

[longdayjake]

Those chambers are pretty loose. I have noticed that I get a lot more soot on my garand, ar15, and m1 carbine brass than what I get from my bolt action rifles.

 

[BlackJackJoe]

Thank you, everyone! I feel better about it now and I appreciate the feedback. Keep shootin' 10s & Xs!