I believe they’re the same gun except the QCB model has been hand fitted in Colts Custom Shop.
From Colt’s website:
http://www.colt.com/Catalog/Pistols/CQBPCloseQuarterBattlePistol.aspx
More than 100 years ago, the Colt 1911 was chosen as the official sidearm for America’s Armed Forces. Today, a Colt 1911 is once again proudly serving at the side of our country’s military. After a rigorous selection process, the United States Marine Corps selected the Colt Rail Gun as their Close Quarters Battle Pistol (CQBP). This marks the first time since the end of World War II that a Colt 1911 is being shipped to the United States Government.
To honor the brave men and women of this important staple of America’s military might, the Colt CQBP will be made available in limited quantities through the Colt Custom Shop. What makes the CQBP stand out is its Desert Tan Cerakoted Stainless Steel Receiver and Slide, Novak® 3 Dot Night Sights and Flat, Serrated Mainspring Housing with Lanyard Loop. The pistol also features an Enhanced Hammer, Colt Tactical Ambidextrous Safety Lock, and a 5” National Match® Barrel.
The Colt Custom Shop performs hand fitting of critical mating parts and each firearm is test fired by the Custom Shop and supplied with the actual test target.
Features
Novak® 3 Dot Night Sights
Enhanced Hammer
Ambidextrous Safety Lock
Long, Solid Aluminum Trigger
Flat, Serrated Mainspring Housing with Lanyard Loop
Desert Tan Cerakoted Stainless Steel Receiver and Slide
5” National Match® Barrel
MIL-STD-1913 Accessory Rail
http://www.colt.com/Catalog/Pistols/RailGun®.aspx
History Meets Modern Era: THE COLT RAIL GUN®
Colt continues to take its battle and time proven M1911 pistol and adapt it to meet the changing requirements of its customers with its model O1980RG – The Colt Rail Gun with Blackened Finish. Where quality and workmanship are demanded, Colt once again meets and exceeds the expectations of its customers. This handgun is outfitted with new and exciting features for the law enforcement community, the shooting enthusiast and the personal defense user. The M1913 Picatinny Rail offers the versatility to attach tactical lights or laser sights to the receiver of the Colt Rail Gun, making it a tactical pistol easily adaptable to any military or law enforcement need. This ability to attach a tactical light also makes the Colt Rail Gun an ideal candidate for a home/personal protection need. The Colt Rail Gun features a Mil Standard Rail, Colt Upswept Beavertail Grip Safety with Palm Swell, Extended Single Side Tactical Saftey Lock, Novak® sights, and other standard features of the XSE series. Colt’s quality continues to be derived from its forged steel receiver, forged steel slide, forged stainless steel barrel, and forged steel slide stop.
Features
Novak® Low Mount Carry Sights with Dots
Enhanced Hammer
Extended Single Side Tactical Saftey Lock
Colt Upswept Beavertail Grip Safety
3-Hole Aluminum Trigger
Lowered and Flared Ejection Port
M1913 Picatinny Rail
National Match® Barrel
Front and Rear Slide Serrations
AVAILABLE MODELS:
O1070RG O1980RG 01070M45