I have no idea what it is or where it came from.(Russian military??) bore is .50.

rifled or smoothbore?

Any engraving or stampings on the lock and/or barrel?

The brass breech is something I have never seen before (but I am no expert at all)

I was wondering is it a brass breach or a brass cover , myself

it is interesting , that seems like it would erode the flash hole rather fast to be a brass breach

Not full stock so probably not military unless officer's private purchase.

Or altered afterwards (think sporterized). The brass barrel band looks military-ish?

Is that a sling stud behind the triggerguard?

So many questions.

I was only kidding re the Russian Miliary. The flash hole is a brass covering over the barrel. The lock has MYAa centred with 1797 on the lower beveled edge. There is and very small what appears stamped NHH (even with a magnafying glass I'm guessing.) The hammer lock is missing (theres a hole just above the trigger) Definitely has sling stud and a cheek plate on the off side.

A close-up of the lock and of the detail on the brass fixtures might be helpful.

I see the catch now on the Flint (This word is unacceptable on Trapperman) (hammer). Older locks of that style were called dog locks. A good picture of the lockplate stamping would be great.

This is a smoothbore. As far as getting a good picture of the stamp I can't get it clear. The stamp is just ahead of the lock and at the seven o'clock possition of the flash hole. The other small stamp is at the very back just above the rear of the trigger guard.

cool looking old gun. could have been for everthing from moose with a ball to grouse with shot. i would look around for someone who could repair it and tell you more about it. looks like the kind of gun a wealthy man would have.

Due to the lack of ramrod thimbles (that I can see at least), I think it may have been a full stock at one time. The brass barrel band may have been added to hold the barrel to the stock after the cut down to serve as a substitute for pins that would have been further down holding the barrel to the stock. I also wonder it the brass at the breach was added to replace a flash hole that was badly eroded from use.

A military musket that has had the former full stock cut back. Agree with EdP on the barrel bands. Not common to see one not converted to percussion. 50 caliber is on the small side for a military gun from that time frame.
Need more info and better pictures.

I don't have any more info. I'm not even sure where I got it. It's been in the back of the gun safe for over 30 years. I just turned 80, got the nine of hearts from the cancer clinic, so I was looking and cleaning out my Man's room as I have no family members that have this type of interest. I'll try to find a way to get better pictures. Thanks to all of you for your input. Jim