
Converting the M1 Carbine Into An AR-15
In August 1969, Thomas Donnell, of East St. Louis, Illinois filed an interesting patent - for converting a M1 Carbine into an AR-15. Donnell explained the purpose behind the conversion in the patent, saying that he aimed to convert an M1 to give it the “overall asthetic appearance similar to the military M-16 rifle or the civilian version of such rifle, namely the AR- rifle.”
He noted that:
“The system which may include components packaged in the form of a kit for the firearm enthusiast to make the conversion on his own, generally uses the barrel and receiver assembly of the M-1 carbine in combination with the components provided by the present invention. A stock is provided which is adapted to receive the barrel and receiver assembly of the M-1 carbine and an upper hand guard will fit over a portion of the barrel and mate with a portion of the stock.”
Along with a new stock the kit would also include an “upper hand grip, front sight and similar accessories” so that the M1 carbine had “an overall appearance which resembles the M-16 rifle.” Donnell even went so far as to design an ‘extension block’ to make the M1′s .30 calibre magazine look like a 20-round 5.56x45mm M16 magazine. Only the M1′s barrel assembly and the receiver remained once the conversion was done.
Donnell even takes the time to discuss the psychology behind the desire for a conversion saying:
“Gun styles are often affected by the style of gun which is employed by military establishments… In recent years, the military M-l6 rifle has received widespread attention. In fact, there is at least one civilian version of a rifle based on the M-l6, namely the AR-lS rifle, and which has substantially the same outer appearance as the military M-16 rifle.”
He continues explaining that AR-15s are complex and expensive to manufacture and buy therefore their is a necessity to create rifles that copy the AR’s aesthetic. At the time surplus M1 Carbines were certainly cheaper than a brand new AR-15 from Colt.
Donnell’s kit design is certainly ingenious but I’ve not been able to find any examples of the conversion so it is unlikely it ever made it to market. Interestingly, Donnell’s patent has, however, been cited by subsequent patents from companies including Colt, Beretta and Mossberg.
Source:
‘Firearm Conversion System’, T. Donnell, 12 Oct. 1971, US #3611607, (source)
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