Many years ago, I started reloading for .44 Magnum with a Lee Loader, a plastic scoop and a pound of IMR 4198. I have no idea why the man who would become my boss in another decade or so started me out with that powder, but that is what I had so that is what I used. Eventually I would discover Unique and 2400, then still under the Hercules brand, among others and that partial container of powder found its way to the back of the shelf while I explored and learned a few things.
In these times of shortages, I found that 2400 and Unique are both apparently made from stuff that comes out of an unobtainium mine, so when I wanted to develop a heavy load for my Ruger/Lipsey Flattop .44 Special, I ended up having to develop my own loads from stuff I had on the shelf or was able to obtain locally.
That partial can of IMR 4198 is still on the shelf. It's a bit dusty, but seems none the worse for wear... and somehow has managed to acquire a couple of latter-day compadres. So, now I have 2 1/2 pounds of powder that was apparently suitable for .44 Magnum loads once upon a time. Of course, in those days, I didn't write anything down and those old IMR powder loading data sheets have long since hit the recycling bins. I remember the load I was using being a bit unpleasant even in my heavy Dan Wesson .44... one of the reasons I started looking into Unique and lighter loads.
After doing a little research, I discovered that some folks have apparently been using IMR 4198 to load for .44-40 WCF... a much milder mannered cartridge than any that I was using, but hey... it seems to work for some.. even in '73 Winchester rifles. Now, the 44-40 WCF has a higher capacity than the .44 Special case, especially when loaded with a plain-base 255 grain SWC, so I started a bit lighter, ending up (so far) with an 18.7 grain load. This seems to be a max capacity load with minimal, if any, compression.
The load is stout and certainly not for Charter Arms Bulldog revolvers, and maybe not for Colt SAA revolvers either, but my Ruger seems to handle it OK. Recoil, although stout, is manageable and not too hard on my hand and wrist. Leading is minimal and the load seems to agree with my sights as to where the bullet goes. Given my old eyes, that is not always a given. I haven't seen any obvious signs of excessive pressure so far. I haven't really done any accuracy testing yet. I can hit a rotten grapefruit at 7 yards, which is about what I wanted it to do, so it's good enough.
Now, I still have yet to acquire a chronograph, so I can only guess at my loads' performance. Anyone else out there care to venture a guess as to my pressure levels and velocity with this load might be?