Just curious if any one has tried the little deringers chambered for 410?  They look like they would hurt.  Is there any other type of really small CCW type of weapon that fires shotgun shells?  

thunder five is the only other one I know of.

Recoil is pretty stiff out of these little guns.
Performance was really weak out of the derringer I shot. The shot string spread out pretty much immediately after clearing the barrel. Range is VERY short. Would be a nasty weapon to be hit with at close range.

Quoted: Is there any other type of really small CCW type of weapon that fires shotgun shells?

You mean like this?

www.serbu.com/shorty.htm

The problem with those is if you want the pistol to be sold as a regular title 1 firearm the barrel must be rifled. This spins the shot cup causing the pattern to spread wildly and way too soon.

They would be fine if one registered it as an AOW and took the rifling out and put in a choke sleeve.

The only shotgun ammo you should consider is made for those gun which has 3 shot pellets stacked end to end which are of large enough diam to engage the rifling and kind of spin like a bullet would. They group acceptably.

I had one, I sold it to a friend.  It was one of the double barrel side by side 410 shotgun or 45 LC versions.  I shot some 45lc through it and it was pretty stout.  I got rid of it because of the cheap ass safety mechanism.  It would sure scare the hell out of someone, but wasn't safe enough for me to carry.