Hi,
What are your thoughts on using cast bullets?
I don't have any real experience loading jacketed bullets below conventional "starting" load levels, so I can't offer anything other than what's already been suggested: look at Hodgdon's and others w/ your fingers crossed?
OTOH, if you're ok w/ using cast bullets, there's a lot of "light" stuff possible. The Lyman Cast Bullet Handbook offers quite a few "pop gun" loads. One I've used a lot is a 180 gr bullet, cast of pure wheelweights and water-cooled, w/ a gas check, over a light charge of Unique. These can be tailored between around 1200-1400 fps, are reasonably accurate at 50 yds, usable to 100 but not so accurate (in MY gun) "out there" because of the trajectory. (They're probably no challenge to a guy who's served on a mortar crew!
)
The recoil's quite light, so they're great for "trigger time" and training purposes if that's what you're looking for.
Then one can step up... if you have or get a copy of Lee's "Modern Reloading" book, there's a formula in there for "downloading" jacketed bullet recipes to use w/ cast bullets. Of the three powders you mentioned, I've used this formula w/ two, IMR 3031 and IMR 4198. I've loaded them in the 1500-1750 fps range, they work quite well to 100 yds, and I can "ring the dinger" at our range (200 yds) pretty consistently after a sighter or two. Again, this is an "in MY gun" report, but I got better results w/ IMR 4198.
And, using Lee's formula, one can actually load 'em up to the point they'd be ok for some hunting uses. For example, while I wouldn't feel comfortable taking a 200 yd cross canyon shot at a deer w/ one of these loads, a tree stand shot of maybe 50-75 yds at a small to medium animal wouldn't worry me.
Used to be you could save considerable amounts of money using cast bullets, too, but that's changing. Wheelweights are harder to find in the "free" buckets, commercial lead's gone up a lot, and gas checks have gone thru the roof. Still, I can produce bullets w/ commercial lead and gas checks for what I "used" to think was a good price for bulk boxed general purpose jacketed bullets (e.g. Remington Core-Lokts), and they give me a lot more leeway for experimentation. And I save my now "precious" jacketed bullets for "more important" usage than just trigger time shooting...
Rick C