I'm looking for some reduced load data for the .458 Win. Mag. I have quite a few 405gr FNGC cast bullets sitting around for my 45-70s. Any suggestions?
5744??

I'm looking for similar info for my 405gr FNBB & the closest I cancome up with is form the first edition Lyman Cast bullet book. The info is for #457483, 395 - 400gr GC. but I plan to use it as a basis to start out with. If you want, I can scan the page & e-mail it to you. There are load listings for the 45-90 and I'm wondering if that cast bullet data could be used in the 458wm as the case capacities seem to be very close. Also the 45-100 sharps capacities. Anyone know?

Greatly reduced charges of slow burning powder in large cases can be VERY dangerous. As far as I know this is because of pressure spikes. If anyone has ever been around heavy equipment all that air in the case is kind of like air in a hydraulic cylinder. Very unpredictable. As the powder begins to burn the air begins to compress this pressure is what causes more pressure if that makes any sense. If there is not enough then the burn "rate" slowes and the bullet can stop in the barrel. But guess what the powder is still burning.

Use something in the 4227-4895 range would be my safe. You both may know more about all this than me, but I figure better safe than sorry. What can I say I'm old and I warn people a lot.

I've had similar desires to be able to enjoy my DGR without the pain....
Two loads I get great results with are:
1.) 350 gn. Hornady JSP over modest charges of IMR 3031 or IMR 4895. Both give best results with 50-52gn charges.
2.) 500 gn. cast, plain base over 50 gns. IMR 4895.
Your results may vary,
ENJOY...
Don

Ruger #1 458 Lott 24 inch barrel. 458 WM case with a 350gr Oregon Trails 'laser cast' non GC bullet. IMR SR 4759 powder (a 'bulky' rifle powder), CCI 250magnum primer. Shot at ~30degrees F.

26gr 28gr 30gr 32gr
1188 1292 1389 1491
1198 1244 1381 1514
1137 1280 1377 1451
1022 1274 1396 1473
1168 1285 1388 1458
1158 1289 1397 1465
1181 1280 1393 1490
1148 1263 1392 1491
1175 1219 1418 1475
1174 1258 1383 1491

The 26 gr loads were the only sooty loads, all the others fired cleanly.

These are the 30gr results at 50 yards, open sites. This combination was the most accurate. You'll notice 7 holes, but the target was hit 10 times.


If you want a comfortable, fun plinking load for the 458 WM, try SR 4759 and some cheap cast bullets.