I receintly ordered and received and new Bushmaster upper receiver from a very highly regarded dealer (they contribute to ARFCOM). Service was excellent. And all of the other parts that were included in my order (which totaled over $700) arrived in good form.

The upper receiver however doesn't have that lubercative film layer finish that my other Bushmaster receiver has (the area inside where the carrier travels). It just seems to be same finish as the rest of the receiver. I can't make a direct comparison at the momement,  I am making this observation from memory, since my other Bushmaster is with Kurt being modified.

Should there be a lubercative film inside the receiver? The lubercative film finish in my older Bushmaster has a grayish, almost silver, hue inside the carrier area and the slot where the carrier key travels. The new one however appears to have the same finish inside and out.

What do you all think?

Thanks!

Yes it should.  That's one thing Bushmaster makes clear about all the uppers Bushmaster sells.  I'd contact the dealer and question this.

Thanks... I will send them email about it..

By the way, only identifiable markings on the receiver is a small "door keyhole" shape on the side with the bolt assit, about 0.5" behind the case deflector.

Also check the barrel marking.  Does it say something like "B MP 5.56 NATO 1/9" ?  The first letter "B" indicates Bushmaster.  Does your have the "B" ?

Quoted: Also check the barrel marking.  Does it say something like "B MP 5.56 NATO 1/9" ?  The first letter "B" indicates Bushmaster.  Does your have the "B" ?

This is just the receiver... it is not yet barreled.

The only marking on the receiver is a symbol that looks like a keyhole or an upside down "U".

That marking is a forge mark. I think it indicates who forged the upper. The one I got from Bushmaster direct has what appears to be a captiol "A". Does your look like that maybe?

Forging mark


Pic of dry film lube on one Bushy upper. Never bothered to check the others.

I'm wondering of Bushie changed the type of dry libe they're using.  The reason I mention it is that I just bought a CM upper that was advertised as also being dry lubed, and at first didn't seem to have anything on it either. However, when I put it under a strong light, I could see some "variations" in the surface coating on the inside, and after asssembling and operating the action a couple of hundred times, the carrier contact areas are not wearing the finish like they do on my non coated uppers.

Is it possible that it's simply a clear type lube? That's what it looks like on my piece.

I really hate doing this.  I hate to sound like a wise ass.  But, I only say this to be constructive.

I order my parts directly from Bushmaster only.  This way, I know exactly what I am recieving.  It will cost a few more bucks, but at least I know exactly what I am recieving is geniue Bushmaster, and someone didn't pull a quick one on me.

Quoted: I really hate doing this.  I hate to sound like a wise ass.  But, I only say this to be constructive. I order my parts directly from Bushmaster only.  This way, I know exactly what I am recieving.  It will cost a few more bucks, but at least I know exactly what I am recieving is geniue Bushmaster, and someone didn't pull a quick one on me.

I agree. I purchase all but lowers from Bushmaster direct and had no problems.

There are many fine dealers who will do you right.  I've done business with Eagle Arms on the EE and purchased lowers.  Eagle is a great business and wil not do you wrong.   Just be careful of where you spend that hard-earned $.  

I used a flash light to look inside the receiver and it appears that it does have the dry lube film. It does appear however that the color of the film is different than that of my older Bushmaster... perhaps the inside of the receiver changes color over time?  or as someone else speculated above, perhaps Bushmaster changed the type of film. The difference in appearance could also be the effect of wear on my older receiver.

By the way, I did email with the dealer and they were very helpful and responsive. I am very comfortable that what I received is indeed a Bushmaster part... and I would not hessitate to order again from this dealer.