Interesting. Since I reload that same hull--which I would shoot in short-chambered 16's if I currently had one--I'd be interested in knowing the formula used. I had mine tested by Tom Armbrust. Avg MV: 1182 fps. Avg pressure: 7420 psi. I've shot a whole bunch of reloaded 2 3/4" 12ga shells in Brit/Euro guns with 2 1/2" chambers. Pressure and MV very similar to my 16ga reload.