THE Navy SEAL and UDT efforts to the MACVSOG program were fairly entensive. For the most part they ran ops out of northwestern IV Corp and southwestern III Corp into Cambodia and southeastern Laos. Most of these ops were not recon rather dircet actions, boobytrapping , enemy POW snatches, etc. The largest efforts were their ops into North Vietnam limited to the south east coastal line. But if you get ahold of copies of SEAL Teams 1 and 2, and UDT11,13,15 Command Histories, you'll get a good read on their operations. Many of these docs can be found in (sorry gave wrong Teas Univ) Texas TEch Vietnam library (but it is not an easy site to work through). But you can also find great references not only to this but to alot of ordnacne info at the Public STINET web site.
Lt Norris's actions have been well documetned for many years now, as have some of Enoch's. But the SEALs operations within SOG were also well known, though not as much as a recon element as the Army's SOG elements. They still brought a lot to the table, especialy the higher tech tools and toys through out the war.
Should be getting more info on the 12 ga silent round, later today. If I can post pdf to this thread I'll put a couple pages or so on