Hello
I have a bag of 500 grain lead cast bullets (coated) that were given to me to develop cost effective training loads for a 458 win mag.
They have been sold as 45/70 projectiles, recomended for 1700 fps MV.

I shot some loaded with 62 grains 2206H (AA2230 equivilent)with mild compression and they chronographed at 1980 fps. Accuracy was erratic and bullets were tumbling. Obviously way too fast!

So to my question:

Obviously to get to 1700 fps I will have to down load. At what point does this down load become unsafe? I am concerned incase of secondary ignition.

Has anyone shot similar bullets and can share their loads?

Any comment appreciated

Stu

I strongly recommend you get yourself a copy of the Lyman Cast Bullet handbook http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=796528 They'll give you tested data with appropriate powders for the job you're trying to do.

IMR 3031 will get you what you want and I have never heard of any detonations with it. I use 51.9 gr to drive a 405 at 1800 in .45-70, and the load is nice and full, but not compressed. I don't think the 458 WM case is so much bigger that secondary ignition or detonation will become a problem.

Thank you gents

Stu

stuey, lyman's manual lists 41 gr of imr 4227 for 1700 in the 458wm. 47 gr gets you 1855. this is with a 482-gr bullet in a ruger no. 1.