i have just did the "cold blue test" on the chamber of a DPMS AP4(M4 style) 14.5" barrel and it appears to be chromed.....at least the chamber.....

i couldn't check the muzzle as the phantom FH on it is permenantly fixed.....but i checked the chamber using cold blue and it appears to be chromed.....i checked the process on a very small part of the barrel extention and it turned almost right away.....checked it on a very small part of phosphated steel( a carrier key) and it turned almost right away......i looked at the chamber and bore in the barrel as much as i could and it appeared to possibly be hard chromed.....but really couldn't tell......anyway, i rubbed blueing all over the chamber over and over and over with nothing but clear liquid results....would not take the blueing what-so-ever...100% not......made sure the chamber was free of oil.....would not take blueing no matter how long you rubbed it on or how long it set......


markings on the barrel are under the hand guards and simply reads: DPMS 5.56mm 1/9....


has anyone else lucked up and recieved what appears to be an unmarked chrome lined DPMS barrel?????


cheers


camaro

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