Is this Fowling?

[Gerrya]

Ive got about 300 rounds through this M4 barrel. This pic was taken at the chamber end and Ive cleaned the crap out of it and this wont come out. I used shooters choice and passed the brush through about 20 times. Its mostly the first couple of inches past the chamber.

[HOGWILD]

Looks to me like melted plastic from crimp on hull that has stuck to barrel and run ya a bore snake thru it and work it just in that area with some Hoppes #9! This happens to mine every time i use it and thats why ya need to keep barrel free of obstructions!!

[tucker301]

I'd try a small amount of Flitz on a bore mop chucked up in a variable speed drill.

[Gerrya]

Looks to me like melted plastic from crimp on hull that has stuck to barrel and run ya a bore snake thru it and work it just in that area with some Hoppes #9! This happens to mine every time i use it and thats why ya need to keep barrel free of obstructions!!

I tried some Kroil and probably about 50 strokes with the Bronze bore brush and it cleared up most of it. There is still a little left, but Im sure it will be that way the next time I shoot it.
Thanks

[johnnywitt]

Fowling=fun; Fouling=not fun... ha ha. Ya, that's fouling allright, no big deal.