Apparently, you do not do much if any bullet casting. I am not using any secret ingredients. Even normal tire weight lead has enough antimony and tin in it to heat treat effectively using nothing but a common oven and a water bath. I do use a hardness detector to check my results and it is necessary to use a gas check on the end of the bullet. I make my own gas checks. One can easily use these bullets in a 7.62x39 cartridge at standard velocities with no leading problems in the barrels.
There is an optimal hardness for a rifle bullet associated with whatever pressure is developed when firing your cartridges. When hardened correctly and used with the optimal charge for the hardness of the lead, cast bullets engage with the rifling more effectively than copper jacketed bullets. If the cartridges are loaded precisely they are more accurate than factory and especially old surplus. The pressures being developed can be accurately determined by using a decent shooting chronograph. And yes I use these in Kalashnikov type rifles all the time.
If you want an easy to understand explanation of the principles involved matching the hardness of your cast bullet to the pressures developed in your cartridge I would suggest you find a copy of Modern Reloading, second edition by Richard Lee. Tire weight lead bullets dropped into water from the mold are actually harder than optimal for many types of pistol bullets.
As far as the economics involved. It is pretty hard to beat surplus berdan primed 7.62x39 ammo. But hand loads with cast bullets and boxer primers are easier on the rifle and not corrosive. For me it adds another dimension and makes shooting much more fun especially when I am perfecting a new cartridge recipe. There is real satisfaction when everything comes together.
Generally 7.62x39 brass can be used several or more times in a Kalashnikov type before you have to start rejecting them. I do anneal the necks to help keep them from cracking especially when they are being used in Kalashnikov style rifles because a certain percentage get dented when they are ejected.
I stocked up on primers, brass, lead and powder a long time ago. Most of my reloading equipment, brass and primers were purchased from Midway USA and the powder came mostly from Powder Valley and Ballistic Products. Do fishermen ever really recoup the cost of all of their equipment and supplies? Saving money was not my first consideration.
7.62x39mm brass currently costs approximately $.65 a piece new; I used to purchase “once fired” brass for a small fraction of that and still get 6 or more reloads out of it on average. Primers are currently less than $.03 a piece if you buy 5000. 8 lbs of powder, enough to load approximately 2,400 cartridges is around $170, about $.07 per cartridge. The lead and gas check cost less than half a cent per cartridge. So you are looking at $.10 for brass per reload, $.03 for the primer, $.07 for the powder and .005 for the bullet and gas check. That comes to right around $.20.5 per cartridge, so this is approximately the same cost as surplus 7.62x39 purchased in a spam can.
If one doesn’t find reloading cartridges to be enjoyable it is not worth it, personally I enjoy it. I have several types of presses and numerous dies for pistols and rifles long with shotgun reloading equipment.
“Apparently, you do not do much if any bullet casting. I am not using any secret ingredients. ...
... If one doesn’t find reloading cartridges to be enjoyable it is not worth it, personally I enjoy it. ...”
I reloaded a great many rounds in some 29 diffferent calibers, from the late 1960s until about eight years back. Cast my very own rifle and pistol bullets. Used various muzzle loaders also. Then cumulative effects from several old injuries caught up with me: disabilities grew to be such that I slowed down and stopped.
fireman15 deserves our praise for keeping at it. Anyone performing cartridge reloading deserves numerous accolades from the forum. That goes double when it comes to casting bullets. Tends to greatly complicate the anti-gun faction’s problems, and multiply confusion for busybody regulators.
I stand corrected on the leading question. Checked some details with a colleague who reloads extensively; he says it is possible to push rifle bullets of proper hardness and suitable dimensions to 2400 ft/sec without encountering leading.
I performed a few experiments with cast bullets for the M1 Carbine, then chanced across technical articles warning against it: heavy leading at 30 Carbine velocities (1950 ft/sec military loadings). I lost interest at that point.
If fireman15 has coaxed any usable accuracy from any average variant of Kalashnikov, he is very much above average. I spent 13 years working for a gun repair firm; many gun owners bragged about how accurate their Kalashnikov clones were, but they never mentioned an actual group size. Not a one of them ever brought us a test target, though we did ask them to, more than once.
Keep up the good work: may you never experience a stuck case.