Our XCR-L Rifles can now be purchsed with our "Burried" or "Type 3" Gas System. The Type 3 Adjustable Gas system was designed so that it can be burried within an upper receiver but still be adjusted from the outside. This allows us to build a maximum length upper reciver for any given barrel length. For example, it allows us to use a 23" upper reciever with a 16" barrel (very appealing to 3 Gun Match shooters); a 17" Standard upper receiver with a 9.5" barrel; and our 15.25" Mini upper reciever with our 7.5" barrel.