Bushmaster Upper Question

[kidao35]

Does anyone know what Bushmaster used to coat the inside of the upper receiver? It appears to be a medium gray, matte finish.

The reason I ask is I noticed some of it starting to peel away in spots after my last cleaning. Its coming off as if it were a paint, vs. some kind of parkerizing. I don't believe I used anything on it I haven't used before (propanol-based brake cleaner, followed by some compressed air). The rifle has is a newer post-ban (XM-15E2) with only about 700 rounds through it.

I don't think it contributes much in the way of lubrication to the bolt carrier, however I am concerned bits of it could foul things up.:confused:

Thanks in advance.

[imanaknut]

From what I remember in another thread, it is only a production coating and will not hurt the function or life of the rifle as it flakes off. Not what I would engineer into something like that, but then again, I am not Bushmaster, and they do have a great reputation for quality.