YO may find some loading data in the Back of any Dixie Gun Works Catalog for the 24 gauge.
I have loading data for the 20 ga. and the 28 ga. in my Hodgdon Reloading manual, and I would split the difference. For instance, the 28 gauge LIGHT LOAD calls for 1 3/4 dram( 48 grains) and 5/8 oz of shot. The 20 gauge LIGHT LOAD calls for 2 drams( 55 grains) and 3/4 oz. of shot. 2 drams of powder( FFG) and 3/4 oz. of shot in the 28 ga. is considered a HEAVY LOAD, while in the 20 gauge, its consierd a Light load. Split the difference and for the 24 gauge, you should find that 2 drams of powder and 3/4 oz. of shot will be a medium load.
Also, go to Bob Spenser's Website, ' Black Powder Notebook",
http://members.aye.net/~bspen/index.html
where he has both his own article on smoothbore loads, and then another article by V.M. Starr on Smoothbore loads, where you will find advice on loads for the 24 gauge.
You can sometimes find that if you use a 3:4 ratio of powder to shot, for a Turkey load, you will get a better pattern. The extra shot slows the velocity some, and that helps make for tighter patterns.
Remember that the 24 gauge is a .58 caliber " Smoothbore" so when checking recommended loads, Don't hesitate to look at data for the .58 caliber rifles. You will need to convert your " Ounce " weight to grains, so that you can find a RB or conical bullet under the .58 caliber rifle charts that are similar in weight to you proposed shot load. There are 437.5 grains to the ounce. So, do your math.
If there is a secret to getting more dense patterns in any Cylinder Bore smoothbore using Black powder, its to reduce the amount of your powder charge for the amount of shot you are shooting. You give up only a little velocity, but the pellets tend to stay closer together. At the very short ranges where Turkeys are shot with BP smoothbore( 25 yds and under) as long as you are using #6 or #5 shot, you will have enough power to kill the birds, even if you are using a " Light " load.
