Welcome to the forum.
Pre-WWI, I think. This model came on the scene in 1911, and this one has a couple of features that point to manufacture no later than 1917 if I recall the timetable correctly (large logo on sideplate, no MADE IN U.S.A. stamp on frame in front of sideplate). I am guessing the serial number is between 138000 and 250000.
Handmade target stocks, as noted above, and probably home handyman sight modifications too. That rear sight has been jacked way up, and the front sight filed to create an appearance that the gun's owner wanted. I wonder if the gun shot way low, and the modified rear sight was designed to correct that problem.
The gun was produced before high speed .22 ammo was produced, so I would restrict myself to standard speed ammo. The gun is not likely to grenade on you, but why stress an honorable old revolver if you don't have to?