RE: 44 special loads
You dont want to use w296 in a 44 special load, I wouldnt even try experimenting with it and you wont find any load data either. 296 is a very touchy powder all of winchesters load data using 296 states to use the exact powder charge listed, for very good reasons too. You will also noticed when loading 296 it fills almost all the case and when you seat the bullet its practically a compressed load, loads are engineered that way for 296 so there is no chance of the primer blowing through or over shooting the powder which can cause extreme levels of excessive pressure that will blow the gun up.
If you want a good powder for 44 special loads try alliants unique or blue dot or Hodgdon clays or clays universal. all of those powders are great for lower pressured straight wall cartridge loads I use them all in 38 specials, 380 acp and 45 acp and the unique and blue dot I also use in 357 mag and 44 mag loads. Have fun and be "SAFE"