Colt Upper Receiver Conversion Kit LE6940CK
Colt MK12 HBAR 18 inch Upper Receiver Assembly
Factory Conversion Kits
The Colt AR-15 Resource
"A site dedicated to the history of the Colt AR-15 rifles, carbines and associated items"
Colt Upper Receiver Conversion Kit LE6940CK
Colt MK12 HBAR 18 inch Upper Receiver Assembly
The Colt AR-15 Resource 