I really hate to say anything against a very popular opinion, but this so called "sweet spot," is the most over used, mostly meaningless, phrase on these threads.
In developing loads in your bolt action bottle neck cartridges, using cast bullets, your top loading is governed by how much pressure your cast bullet can stand. Load too much pressure behind it and it will actually blow a rut in the bullet, the length of the bullet and let pressure escape, even with a gas check bullet. The rut down the length of the bullet will be at least half, or slightly larger, than the wood in a kitchen match. When this happens, the bullet, of course, will be a large flyer, like a foot or so, at a hundred yards.
I am not guessing at the information above. Nor did I read about it, or has anyone told me about it.
The above information comes from my own experience. I was the only shooter one winter, shooting cast bullets at the range. In the spring I could pick up my bullets, most of which were completely unharmed from hitting, because they were stopped by the snow and could be carefully examined.
I found several with this rut cut through them, which would obviously be the wild flyers I experienced.
Other bullets, loaded too high, but not enough to blow the rut in them, had slipped a bit in the rifling. I took it that these bullets would come from using a bit too much fast powder, started too rapidly. Probably one reason some of my most accutate loads was with the super slow, H4831 powder.
The most accurate loads in the rifle would be those loads that were as heavy as they could be, without damaging the bullet.
ed and cast hard was great!
