I use it in my 45-70 levergun and have plenty of it. Well, I was looking at an old Lee load kit for my 44mag and the data was printed in 1963. Low and behold they have an load for the 44mag using IMR4198. I could find it in anybody my old Speer or new manuals I have now the Lyman cast book.

This may not be the ideal nor best powder but if it works and a person has some why not use it? So would that be a go or no? It might be ok as it's primary use is an Marlin 1894 SBL.

Going to be some granules left over and I would definitely use a magnum primer.

I don't know why there would be such a load, other than to have a minimum REDUCED load.

Its pretty ineffecient in that cartridge even with a caseful.

I seriously doubt if you're going to get consistent ignition in the .44 mag with propellant that slow. Velocities will be all over the place. AA1680 is faster than 4198 and I had very good results in the .357 Maximum with AA1680 but I had to use a case full to get it to burn consistently. I tried it in the .357 Magnum and couldn't get enough of it in the case to burn properly.

Even the slower propellants that work well in the Magnum handgun cartridges, such as WW296 have to be loaded high end to make them burn consistently.

I was very surprised to see IMR had a load with 4198 as well as other slower powders. It's in the rifle data, not handgun.

IMR

4198 is not abundant right now, I’ll bet you can find someone who will trade some real pistol powder.