I load 25 grains of H4895 under a 150 grain Hornady SP Interlock bullet. This load is very reliable, and accurate out of my Simonov carbines. I am not sure about the hunting aspect though, as I do not hunt.
If you are after deer sized game then bullet selection is very important. The 7.62x39 in the Mini-30 has a velocity about 2200-2350fps with lighter bullets in the 125gr class and about 2000 to 2200 in the 150gr class. For a bullet to be effective it must be able to expand and penetrate at these slower velocities. That puts you in the 30-30 class bullet or a Ballistic Tip type bullet. If you are hunting smaller critters then bullet selection becomes easier.
I shoot .308 bullets out of my Mini-30. This gives me a much larger selection of bullets to choose from. They also shoot better in my mini then the .310-.311 bullets.
When I owned an SKS, I used the Sierra 125gr FPHP intended for .30-30 use. This bullet cycled perfectly in my gun and was accurate. A heart/lung shot on a whitetail was always fatal.
I can look up my load data tonight if you want, but I don't think it will help you much. I was using Accurate Data 2200 powder. A surplus powder that doesn't seem to be available any longer. Accurate 2230 or IMR-4895 should work pretty well.
In the U.S., most states prohibit the use of steel core or Full Metal jacket ammunition for hunting deer, pigs and other large game. Expanding bullets are required for humane kills. Some areas allow Buck Shot, but it must be lead or copper coated lead. Steel, Bismuth and Tungsten alloys are used in large birdshot sizes for waterfowl. In short, here 12 ga steel ammo is not approved for hunting deer.
Personal Protection is another matter altogether...
I've wondered not about hunting, but loading up a 7.62x39 version of the 300 AAC blackout.
Use a large 308 bullet, and keep it just under the speed of sound. With a expanding design, it would be quiet, and quite effective on deer too. (Something along the size of 300gr. with a ballistic tip?)
All I've used is Herter's SP and HP ammo, as well as Wolf HP and of course lots of ball and some AP loads from Egypt that were so hot, they really tear up the range stands. (IE cut metal in half when you really did not mean to.) The Egypt stuff had really hard primers that the Mini 30 did not always like on the first try too. (Firing pin does not protrude enough stock, as Ruger is worried a longer pin will puncture domestic loaded ammo.)
about the most informative poster concerning the x39 was steve4102.
he got banned due to razeing hell about the trolls here when the site changed hands.
also some other good members went out the door, or were banned.
I've posted my 150gr speer spfb load earlier. myself I feel the 123gr vmax to be too light for large whitetail over 100yds unless full profile shot presents.
So, nobody has done a sub sonic load for this round? Should be easy to load, the cases will take 308 bullets easy, and to get the right OAL, just push the longer, heavy bullets deeper into the case. Imagine a 300gr subsonic round. Would be a massive hitter inside of 100 to 150 yards.