I just spoke with Stiffi and the release date on their new MF (Metal Free) barrels is February 5th, 2009. They should start shipping them then and we should have them in stock ready to ship about a week later.
Also an update. The A5 version IS NOT available in the .689 bore size. Stiffi doesn’t make any A5 barrels with .689 bores to accomodate the larger Tippmann bolts.