The 2 3/4" and 3" chamberings were generally used for waterfowl or pigeon shooting, but a shooter could of course order a gun with 2 3/4" for game shooting as well. The shot charge stampings were used until they were replaced by the Tons Per Square Inch stamping under the 1954 Rules of Proof.

You have a very nice SL there. You can also used 2 1/2" RST loads available here in the States or load your own low pressure 2 3/4" loads.

Best of luck to you!

Greg

Gregory J. Westberg
MSG, USA
Ret