Steer clear off the velocity rims.They will strip out very easily.I would go for the Outback Weld TXT-1 40 series wheels.Savage-Central.com sells adapters for these wheels and they have held up for 3 gallons on mine so far and thet show no sign of giving up any time soon.
i hjave the velocity and havent had a problem that just might be cause i hjave the .21 but had no problem yet and had it for about a month and and gallon and a half