So I recently bought a 17s and have had it out at the range a couple times and have put about 100-120 rounds through it. I noticed when cleaning that there is a blemish on the front site. It appears to be soot like and i noticed there is a bit on top of the gas block as well which it looks like it might be coming from. When i took the piston out i did notice a similar brown inside the gas regulator and block which seemed to come out easily enough with a dry wipe and a bit of brushing with a bronze brush. I have the gas regulator set to the 12 o'clock position as per the manual. My question is is this normal, something that will clear with a bit of breaking in, or something I should possibly be concerned about?