stanway: The 358 is one of the greats for shooting cast bullets. The slower barrel twist (compared to smaller calibers) is just plain good for cast bullets as they keep the RPM's down.
A sure way to be disappointed with the results of shooting cast is to start with loads that are excessive for the bullet material. Standard jacketed bullet loads mostly fall into that category. There are ways to shoot cast at high velocity but the lessons are hard learned and involve a lot of tinkering with powder, primer, bullet alloy, lubes and sometimes case fillers. For the most part the best accuracy with near max velocity will come with slow burning rifle powders and some of the best are probably omitted in the jacketed bullet loads as being too slow burning for that purpose.
Start with a load at the 1400- 1500 FPs level and work up until your accuracy goes south. This is liable to be in the 1700-2000 FPS range. you will not be disappointed with accuracy if you approach that way.
A good powder to try is either IMR4895 or H4895. Hodgdon has a guide line for reducing loads with 4895. I believe it is 60 % of their starting load for the bullet weight. You should check this at the Hodgdon site in case I have it wrong and it's 60% of max load. 2400 is another powder that can give good service with cast bullets in the neighbourhood of 1600 FPS. Try to get ahold of a good cast bullet loading manual (Lyman, Lee, RCBS etc.) to get yourself started. Also remove all copper fouling from the barrel before you start shooting cast. If you are able to slug your barrel it would be advisable to order bullets .001-.002 larger than actual groove diameter of the barrel.
