I am suddenly very enthusiastic about LC Smith shotguns. I have a smorgasbord collection of Spanish SLEs,a couple of Italian boxlocks, and a couple of Winchester SxSs but his 1909 Smith has some character, too. I will be pleased to find that it has 2 3/4 in chambers; I load a 7/8oz load of Greendot that is fast and about 7000 lbs pressure and I have always loaded it in 2 3/4 cases. I use the 2 1/2 in cases in a couple of light weight Spaniards and shoot preserve birds over a couple of personal E. Setters. The good life. This Smith will make a great dove gun or wildfowl gun with its F and F arrangement. It makes one wish for Fall. I will post what I find about the chambers, as requested.