Robb,
The Navy ordered the Teams the Berreta Brigadiers and they flat out REFUSED them. Around 1998-1999 the Teams ordered 1,500 of the "blackened" stainless slide P226's. The SEALs will not part with the P226 anytime soon. The Sig is very well liked. The only shotguns I've seen in use are Benneli's and souped up 870's.
Gunhead,
It is very common for people to think the Teams can use whatever they like.Not true. Everyone uses ISSUED weapons. The issued sidearms are the Sig P226(most common),H&K MK23 and the S&W 686.
BTW. The P226 is not the M10. The P226 does not have a designation. The Army & Navy did adopt the Sig P228(M11) for personell with hands too small for the M9.