google shows this-this is mostly about M14 stuff but it looks like they did a run of ar15 lowers. I would be curious to know if it's pre ban. Otherwise lots of companies have lowers made with their name on them.

Armscorp of America, Inc. and Armscorp USA, Inc.


Production and Services – Armscorp of America, Inc. was formed in 1981 by Jack H.


Friese. It built accurized M14 type rifles for competition shooters. In 1985, the company


was located at 9162 Brookville Road Silver Spring, MD 20910. Mike Gruber and Clint


McKee, who would later go on to establish Fulton Armory, also worked at Armscorp of


America at this time. The company moved to 4424 John Avenue Baltimore, MD 21227 at


some point between September 1987 and 1992. The firm reorganized as Armscorp USA,


Inc. in 1992 after the move to Baltimore.


Smith Enterprise, Inc. sold some billet machined receivers to Armscorp of America, Inc.


about 1985 and 1986 but none were stamped Armscorp of America. They were Smith


Enterprise stamped receivers and advertised as such. A complete rifle with a Smith


Enterprise receiver, all USGI parts and a used USGI stock was advertised by Armscorp of


America initially in Shotgun News for $539.95. The Armscorp of America advertisement


listed the bare Smith Enterprise M-14 receiver for sale at $199.95 and complete USGI


parts kits without the receiver for $239.95. A TRW M14 parts kit was an additional


$10.00. The customer demand for the bare receivers and assembled rifles was so great


in 1986 that it took the firm several months to fill the backlog of orders even with a price


increase. The June 1986 Soldier of Fortune review of the Armscorp of America M14 lists


the retail price for the Armscorp of America M14 at $674.95 with a used USGI stock.


Smith Enterprise sold some casting equipment and tooling to Armscorp of America, Inc.


between 1986 and 1990. Armscorp of America, Inc. was manufacturing investment cast


receivers at some point by the summer of 1987. As of September 18, 1987 the company


had completed the machining of five lots of Armscorp of America M14 type receivers


using its own personnel and CNC machine tools. Armscorp of America receiver heat


treatment was performed according to the USGI procedure and certified by the vendor.


Armscorp of America receiver with serial number A00326X has been identified as billet


machined. An Armscorp of America receiver with serial number A0039XX is investment


cast. Armscorp USA, Inc. manufactures standard, rear lug and double lugged receivers.


It was the first commercial manufacturer to sell factory new lugged receivers (see H&R


Gun Co. and Smith, Ltd.). The firm casts and machines its receivers as well as those for


Fulton Armory. Armscorp USA heat treats its receivers to 56 to 58 HRC to a case depth


of 0.012 " to 0.018 " per the USGI receiver drawing. Armscorp USA also provides M14


gunsmithing services such as rifle assembly, barrel installation, stock bedding, National


Match trigger and flash suppressor modification, and clean and lube. Note that the large


majority of Armscorp brand M14 receivers have been sold by the manufacturer as


stripped units. In 2006, Armscorp USA was investigating the possibility of manufacturing


a number of forged M14 parts.


Receiver Markings - Some of the Armscorp receivers are stamped M21 or XM25 instead


of M14 NM or M14 to allow for sale in New Jersey, USA. The State of New Jersey,


curiously, has banned new sales of some firearms by name rather than by operating


characteristics or features. The USGI M14 receiver drawing numbers 7790189 and


7790189 F have been found on Armscorp receivers under the stock line on the right hand


side. Stampings on Armscorp receiver operating rod channels have varied. Until at least


serial number A003***, the Armscorp receivers are stamped SILVER SPRING MD.


The operating rod rail stamping changed to ARMSCORP OF AMERICA SILVER SPRING


MD by serial number A0035XX. The next operating rod rail stamping is ARMSCORP OF


AMERICA BALTIMORE MARYLAND. This information is stamped on a receiver with a


serial number as low as A0039XX. The fourth operating rod rail marking is ARMSCORP


USA BALTIMORE MARYLAND as found on receiver serial number 1072X. The fifth


variety is ARMSCORP BALTIMORE MD as shown on receiver serial number 11***.


Armscorp has issued custom receiver serial numbers in the past and still will today upon


customer request. At least one Armscorp custom receiver serial number was preceded


by the letter A. The serial number prefix A denotes a design change in the early receiver


production at Armscorp of America, Inc. The serial number prefix S indicates the receiver


is made of stainless steel instead of AISI 8620 alloy steel.
Taken from: M14 Rifle History and Development