I have a 2-1/2" chambered 12-gauge
I think the intent of your original post was that you are looking for something to shoot in your 12 gauge w/2-1/2" chambers. I have never heard of that chambering (probably 2-9/16"), but, unless it does not have Damascus barrels and is suitable for smokeless powder, you might be good to go with this if you reload shotshells and can find suitable components.
My little story:
My Dad had a Winchester Model 12 field grade in 16 gauge and always wanted at least one more shot in the magazine ( I don't know why as he always only got two shots off on one pheasant).
Back in the day (69-70) I reloaded both 12 gauge once-fired Federal papers and Rem Shur-Shot plastics. The wads I used were plastic Pacific Verilite one-piece wads (and I surely doubt that Pacific is in business anymore: the CEO was Bob Dietemeyer). The Rem hulls were high base (not to be confused with high brass) and the Federal paper hulls were low base, like a Win AA hull.
I created a short (2-1/2") shotshell with the Federal cut down papers (star crimp) using the Rem wads for 1-1/8 ounce loads. Loaded them all using a massive single stage Herter's press (my Dad's). My load was 18 grains of Hercules Red-Dot, which was about a 3-dram load. This was for my Rem 870 and it ran well in a 2-3/4" chamber gun.
I could never find enough 16 gauge hulls as pickups on the range to experiment with that combo, no one had any one-piece wads available for a 16 gauge, but I did show that short shotshells worked in an 870 2-3/4" barrel. My Dad conceded. Long ago...
With a SXS you won't have any problems.
Hope this helps you Mr. Pearce.
Jim