should i be concerned ?

[TIMBERTRAMP]

 I brought ,a used  win94 trapper 45lc last week ,and tried it today using ultamax and win cowboy ammo as well as win silvertip but became concerned when i picked up my empties all of them had a blue \powder mark starting at the mouth and extending down about a third of way on one side of the case i thought it might be a dirty chamber mouth as the barrell was pretty dirty when i brought the gun but it seemed to clean up well so i recleaned the chamber area but it didn't change anything when i shot it a second time the gun seems to shoot ok otherwise though should i be concerned that i brought a gun with a eroded chamber mouth would this be repairable or is this grounds for returning the gun,please .advise-tt

[Smokin Joe]

Probably low-pressure blow by. Keep shooting

[Castaway]

I agree with smokinjoe5150.  Most shooting with my Trapper is with low pressure loads, giving only 820 f/s.  My cases are marked with carbon on one side due to the case not expanding enough to seal the chamber.  When I pump up the volume with hunting quality loads, it disappears.

[TIMBERTRAMP]

Thanks for the info.,i thought at first i may have brought a dog,can't wait to try some hunting loads. thanks again -tt