Here is the link for Hodgdon powders for loading 1 ounce round ball slugs using ONLY the 2 and 3/4 inch shell. the top load is for 1550 fps using Universal Powder.

http://data.hodgdon.com/shotshell_load.asp

Enjoy!

I know with a 3 inch shell you can get a variety of loads/ powders that will get you that magical "over 1500 fps" with a round ball payload. And, again, from past experience the recoil was not that bad at all.

Here is a 3 incher load I got off the hercules website using 46 grains of BLUE DOT powder: 1 3/8 ounce load will get you a velocity of 1,564 fps, using Fed 209A, 10,700 pressure... I'd just visit some of these powder websites to get you some loads.