Cast Bullet and Trail Boss loads in my .458 Win Mag

[zephyr]

here is the recommended method for determining your reduced load using Trail Boss

 

[Ray B]

I didn't see it listed on the link but I recall reading somewhere that trailboss is NOT to be compressed. It can be loaded up to 100% capacity, but no more than that.

 

[zephyr]

Graeme Wright found out the compressing Trail Boss was not to be done

 

[Chuck Kazen]

Have you tried Alliant Unique? It works well in straight walled cases. My old Lyman 45th edition has cast bullet data for the 45-70 and 458 winnie. I generally load 16 grains behind the Lee 405 grain in the 45-70 and 21 grains behind the Lee 500 grain in the 458. I haven't chono'd these loads but both should be going 1300-1400 fps. The 458 is a Ruger no1 - obviously no feeding problems. But I sometimes load the Lee 500 grainer in a 45-70 Winchester 86. Again no issues, flows like water through the rifle.
These are not compressed loads in either cartridge. Also, Unique doesn't require a wad to hold the powder charge in place as some powders do.

 

[zephyr]

Terry Wieland in his book "Dangerous Game Rifles" is a big fan of 5744 for reduced loads. You find the load the same way as with TrailBoss except with 5744 the multiplier is .40

 

[Ray B]

I've never used 5744 but that sounds very similar to SR4759.