AMtrico - the chamber length is a minor issue relative to what ammo you use. Modern experience shows that the actual pressure of the loading is much more important than chamber length. 2 3/4" chambers (original or reamed) DO NOT make an older gun suitable for modern SAAMI standard (USA loads) shells. Also, do not assume that SAAMI factory loads with light shot charges have low pressure. Older guns were designed and made from materials suitable for typical black powder pressures. Such pressures (and lower) are easy to achieve with modern loading components. You do want shells of both low pressure and light shot charges. This is an older gun for sure.
If you desire to shoot it, it will need to be carefully checked by a good double gun smith and it will need correct ammo. Again, knowing chamber length is not sufficient information for sellecting shells. If you get a green light from a smith and want ammo, ask here and there will be plenty of recommendations that will work properly.
