What does this marking mean on an AR receiver?

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[ARCHIVED THREAD] - What does this marking mean on an AR receiver?

Posted: 1/18/2015 9:24:36 PM EDT

While there may be over fifty different AR lower and upper receiver brands, I read they are all made by under 10 foundries in the US. This mark in the picture, the old fashioned key hole is present on all my receivers, DDLES, Mega, etc but not on my Stag receivers. Is this a mark by a foundry? Maybe all these receivers cast at one foundry? Any ideas?

Posted: 1/18/2015 9:28:11 PM EDT

[#1]

Means it was forged by Cerro

ETA link, http://www.cerrofabricated.com/Markets_Firearms.htm

Posted: 1/18/2015 9:28:19 PM EDT

[#2]

Cerro Forge

From osprey21:

Forging marks/makers:
A (splintered) = Anchor Harvey Aluminum
AF = Alcoa Forge
C AF = Colt Alco Forge
C MB = Colt / Mueller Brass
Cardinal (stylized) = Cardinal Forge
CH = Colt Harvey Aluminum
CK = Colt / Kaiser Aluminum
Circle/Crooshairs w/"AR" = ArmaLite
CM = Colt / Martin Marietta
D (stylized) = Diemaco
DK = Diemaco / Kaiser Aluminum
E = Emco
EK = EMCO/Kaiser
E MB = EMCO/Mueller Brass
F keyhole = FNMI / Cerro Forge
FA = FNMI / Anchor Harvey
FK = FNMI / Kaiser Aluminum
FM = FN/Martin Marietta
FMB = FNMI / Mueller Brass
Keyhole = Cerro Forge
L = Lewis Machine & Tool
LK = LAR / Kaiser Aluminum
LM = LAR / Martin Marietta
M (under diamond) = Mueller Industries
PA = Capco / Anchor Harvey
PM = Capco / Martin Marietta
Square = BAFE

Posted: 1/18/2015 9:59:28 PM EDT

[#3]

My PSA blem upper has an plain letter "O".

??????

Posted: 1/18/2015 11:35:15 PM EDT

[#4]

Quote History

Quoted:
Means it was forged by Cerro
ETA link, http://www.cerrofabricated.com/Markets_Firearms.htm

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+1

Posted: 1/18/2015 11:36:21 PM EDT

[#5]

Quote History

Quoted:
My PSA blem upper has an plain letter "O".
??????

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Haven't figured out who there are yet, someone new, would love to know!

Posted: 1/18/2015 11:37:14 PM EDT

[#6]

Thanks It looks like they make Mega, Double Diamond Law Enforcement Supplies (DDLES) and Anderson receivers and/or lowers I have on my guns, among others. All of them seem to be highly competent pieces. Work as advertised.
Also interesting that they make the Ares SCR rifle receiver (The one that has no shell deflector and drove me crazy as a lefty handed shooter) . I just replaced my SCR receiver with and Anderson that had a shell deflector and both were identical except for the bump and cast by the same folks.
j

Posted: 1/18/2015 11:52:24 PM EDT

[#7]

my Stag has an SA

Posted: 1/18/2015 11:55:13 PM EDT

[#8]

Forge mark.

Posted: 1/18/2015 11:55:30 PM EDT

[#9]

Quote History

Quoted:
Thanks It looks like they make Mega, Double Diamond Law Enforcement Supplies (DDLES) and Anderson receivers and/or lowers I have on my guns, among others. All of them seem to be highly competent pieces. Work as advertised.
Also interesting that they make the Ares SCR rifle receiver (The one that has no shell deflector and drove me crazy as a lefty handed shooter) . I just replaced my SCR receiver with and Anderson that had a shell deflector and both were identical except for the bump and cast by the same folks.
j

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They don't make the receivers. They make raw forgings. The companies that make the receivers then take that chunk of metal that is shaped somewhat like a receiver and machine it into a receiver. Which forging mark is on your receiver means pretty much nothing.

Posted: 1/20/2015 2:37:43 AM EDT

[#10]

Thanks for asking this. I noticed the same mark on the upper of my Ruger SR556 and was wondering what it meant.

Posted: 1/20/2015 3:14:54 AM EDT

[#11]

Quote History

Quoted:

They don't make the receivers. They make raw forgings. The companies that make the receivers then take that chunk of metal that is shaped somewhat like a receiver and machine it into a receiver. Which forging mark is on your receiver means pretty much nothing.

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That. The forging is just raw material. To put it another way, it's kind of like they're the guys who supply the rolls of steel that become car bodies. The bodies are made from that material, but the supplier didn't "make" anything.
FWIW, my Colt has the Cerro Forge mark.

Posted: 1/20/2015 3:25:21 AM EDT

[#12]

Quote History

Quoted:
Thanks for asking this. I noticed the same mark on the upper of my Ruger SR556 and was wondering what it meant.

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WHOOPS thought i was in GD. my apologies

Posted: 1/20/2015 4:00:37 AM EDT

[#13]

Quote History

Quoted:
My PSA blem upper has an plain letter "O".

??????

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my question too. no one knows yet??

Posted: 1/20/2015 5:10:20 AM EDT

[#14]

Quote History

Quoted:

my question too. no one knows yet??

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Quoted:

Quoted:
My PSA blem upper has an plain letter "O".

??????

my question too. no one knows yet??

its for Obama, b/c you didnt build it

Posted: 1/20/2015 5:16:16 AM EDT

[#15]

^ its has been asked a few times, but i dont think PSA has commented on the details.
other than its just a supplier of theirs

Posted: 1/20/2015 9:45:27 AM EDT

[#16]

good information here. never knew what it meant!

Posted: 1/20/2015 12:25:33 PM EDT

[#17]

Quote History

Quoted:
My PSA blem upper has an plain letter "O".

??????

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All my PSA uppers have a Square forge mark. I've not seen any of their uppers have an "O".

Posted: 1/20/2015 1:31:48 PM EDT

[#18]

Quote History

Quoted:

My PSA blem upper has an plain letter "O".

??????

View Quote

Last May, I sent an email to PSA asking about the "O" mark. Their reply:

"Sir, I apologize that I am not able to answer your question fully due to it being proprietary information. I unfortunately cannot release any information as to who forged the receiver. Thank you for your business and have a good day."

Posted: 1/20/2015 1:59:16 PM EDT

[#19]

Quote History

Quoted:
Cerro Forge

From osprey21:

Forging marks/makers:

A (splintered) = Anchor Harvey Aluminum

AF = Alcoa Forge

C AF = Colt Alco Forge

C MB = Colt / Mueller Brass

Cardinal (stylized) = Cardinal Forge

CH = Colt Harvey Aluminum

CK = Colt / Kaiser Aluminum

Circle/Crooshairs w/"AR" = ArmaLite

CM = Colt / Martin Marietta

D (stylized) = Diemaco

DK = Diemaco / Kaiser Aluminum

E = Emco

EK = EMCO/Kaiser

E MB = EMCO/Mueller Brass

F keyhole = FNMI / Cerro Forge

FA = FNMI / Anchor Harvey

FK = FNMI / Kaiser Aluminum

FM = FN/Martin Marietta

FMB = FNMI / Mueller Brass

Keyhole = Cerro Forge

L = Lewis Machine & Tool

LK = LAR / Kaiser Aluminum

LM = LAR / Martin Marietta

M (under diamond) = Mueller Industries

PA = Capco / Anchor Harvey

PM = Capco / Martin Marietta

Square = BAFE

View Quote

I've also encountered a "M" that I believe is for "Moore Machine"/Bear Creek Arsenal.

Posted: 1/20/2015 5:22:23 PM EDT

[#20]

Quote History

Quoted:
My PSA blem upper has an plain letter "O".

??????

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If Palmetto would just tell me it doesn't stand for Olympic Arms, then I'd be happy...

Posted: 1/20/2015 8:02:29 PM EDT

[#21]

Quote History

Quoted:

If Palmetto would just tell me it doesn't stand for Olympic Arms, then I'd be happy...

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Quoted:

Quoted:
My PSA blem upper has an plain letter "O".

??????

If Palmetto would just tell me it doesn't stand for Olympic Arms, then I'd be happy...

I don't think Oly forges anything themselves.

The do however makes some famously crappy lower receiver castings.

Posted: 1/20/2015 8:39:44 PM EDT

[#22]

Wonder what they use if anything http://www.uniforaluminum.com/marketsserved_firearms.html

How about this company? http://vindicoprecision.com/forging/

Posted: 1/20/2015 9:08:49 PM EDT

[#23]

I have an Anderson lower and a YHM upper, both have the Cerro mark on them.

V

[ARCHIVED THREAD] - What does this marking mean on an AR receiver?

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