I have loaded my many long colts from powerpuff loads to fire belching frame stretchers!! I do not like to post loads as mistakes so easily happen and I would truly hate for someone to be hurt with something I caused. But Ill still offer some suggestions of where you can start.
For loads Unique and Trail Boss are tops for "colt" level loads to say 900-1000fps with a 250+- grain bullet. These are best with Lead. If you want jacketed loads, IMR 4227 can make you some really efficient loads. Regular primers are the rule here.
Medium level loads say mild ruger loads. You have many powder selections. I still like IMR 4227, but 2400 is another good consideration. Regular and mag primers used here.
Heavy loads are fine in your gun, look to W296, H110 and Lil'Gun powders. Magnum primers are the rule with these loads.
For bullets, you mentioned casting your own. This is a good way to enhance the total experience knowing you built the load and the bullet! Look for a profile with a large meplat. Something like a LTB bullet is an excellent choice. I also much prefer the 300gr weight. You have already mentioned shooting to 100 yards and this weight will deliver the goods easily at these ranges. For Jacketed offerings, look at the Hornady, Sierra and Speer 300Gr slugs. I have shot game with them all, the Speers have been the softest and easiest to expand with more of a plating than a real jacket. the Sierra and Hornady seem similar to me and expand and perform well on game exactly the sizes your describing.
My guns preferred loads are pushing 300Gr slug to almost 1300fps in my 7.5" Ruger Bisley. This same load scoots along at better then 1600fps from my Marlins and Handi. Tim is posted many times about a near max load of Lil'Gun and Velocities to 1900fps. From a Handi barrel.
There are LOTS of loads out there, get yourself a good manual or two, don't worry about the pistol only listings, Start lo and work up as your shoulder permits as you likely will see this before you reach a load that too hot for the gun.
