In this quick video I examine a Crossfire RamRod barrel which dates to about 2000-2002.
This barrel is threaded for the an ACI Griffin (and compatible with a F4 Illustrator and Tippmann A5?). The date on these barrels is likely around 2000 and you typically see them available for Spyders, cockers, and Tippmann paintguns.
Total usable barrel length is about 4 inches and the cage is actually constructed from welded stainless.
Find a review of the Crossfire Ramrod barrel at:
http://www.jchoefer.com/paintball/reviews/ramrod.htm