Ah. Right...we need solid rocket fuel in the .32
.
Right, that seems...possible
.
<scratches head>
I hear what you're saying re: nose heavy, although the spin you'll get on the rifling might help? Otherwise, use a .357Maximum as the "launch caliber", use a 32H&RMagnum as the basis for the flight platform. Pour 65 grains of liquid lead into the shell, drill through that lead up from the primer hole, shorten the case a bit, put rocket fuel in, then cap it with a 60grain JHP. Now you've got something with lead at EACH end, fuel in the middle...the fuel packed in so tight the forward lead (JHP) can't compress under the initial G-forces as the 357 launches it. Granted, your powder capacity on the 357Maximum is a bit limited, but we're only dealing with a 170 - 180grain projectile here...we can get that moving at least around 1,200fps before the rocket kicks in?
Waitasec, let's back up here. The Gyrojet rounds "basically worked". They got peak velocities pretty much on par with handgun ammo, and that was using rockets from a dead stop. I've seen Gyrojet rounds at a gun show, they had a row of nozzles around the rear edge of the round. Most of the weight seemed to be rearward with the fuel forward or in the middle somewhere, so that makes sense.
So they basically solved the problem, except that since it wasn't going very fast on clearing the muzzle, accuracy sucked. But what if the same sort of round had been kicked off with an initial .357 or whatever blast? Boost it past 1,000fps at the muzzle, then get 2,000+ at 20 feet?
OK, fine. How small of a model rocket engine can you get, anyhow? Small enough that you can shove it in the end of a .45-70 case and launch it with a Magnum Research BFR?
With a copper penetrator nosecone of course
. Maybe shorten the shell so you've got a projectile maybe an inch and a half long. Or start with a .444Marlin version, that's a straight-wall case instead of a taper I think?