3100 to 3500 fps sound awfully fast out of a 14" tube. The fastest load I can come up with to meet your requirements is a max load of 27.0 grains, compressed, of H4895 under a 53 grain Sierra HP. It books out at 2965 fps. As a matter of fact, there is only one load on Hodgdons pistol load site that is over 3100 fps. And that is a 40 grain Nosler Ballistic Tip over a max load of 27.3 grains of benchmark for 3174 fps. I think you need to come up with a slightly new set of standards before you jump into this project. Just remember to be careful and safe.