i have an old gun, no markings. it detaches from a longarm into a pistol. ive looked at tens of thousands of pictures of guns and nothing resembles this. anybody know what i have?

Wow, that is a unique piece. You should contact the NRA / American Rifleman and send them these pics. This would be a great topic for "I have this old gun" segment on their TV show. Looks to me it is an early version of a 'take down' gun for ease of travel.
Let us know what you come up with.
Also, you may want to post this in the muzzleloader section as if looks like it is definately a front stuffer.

I agree with a takedown long gun, and not intended to be used as a pistol. Interesting looking gun.

Is it a muzzleloading shotgun?