I posted a message here last night that have been cut off due to a wifi issue.
To my limited knowledge, US Navy SEALs in the "Teams"(even #s US east coast, odd #s west US coast) carry a number of different pistols & weapons based on the mission(s) or deployment requirements.
In general the SIG P226R 9mm, the P228/M-11 9mm compact, the Kimber alloy frame compact 1911a1 .45acp & the big HK USSOCOM Mk 23 .45acp are used a lot.
The US Navy SWCC or specwar combat crewmen; the special boat crew members who transport spec ops units by watercraft use the M-11 compact sidearm & the HK Mark 23 .45acp. The USMC Special Operations Command issued the big Kimber Desert Warrior 1911a1 pistol but that may have changed.
The CAG or Combat Applications Group & the Navy's elite DEVGRU(Development Group), the counter-terrorist unit use the Glock 21 .45acp, the 1911a1 .45acp & a few new HK45 compact .45acp pistols for PSD(bodyguard details) or covert ops.
The standard M9 9mmNATO is also used by spec ops but not that much.
The S&W .357magnum revolvers were common in the 1960s/1970s/1980s. The Teams used custom black coated revolvers for water-borne operations; oil rigs, ships, piers, etc.
For more details read Rogue Warrior, First SEAL, Combat Swimmer, or Red Cell. Former SEAL officer; Richard "Demo Dick" Marcinko can offer a lot of insight.
www.DickMarcinko.com .
If you have the time and are in southeast FL, visit the US Navy SEAL/UDT museum in Fort Pierce.