Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!
Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.
Well, since you asked such a broad question - the French were in Vietnam before we were, and they mounted 40mm Bofors on CCKWs.
More to what you are after, a few gun trucks were equipped with a pair of GE miniguns. Not the largest caliber, but assuradly the most fire power.
Regards,
David Doyle