Need some info on reloading the 458 WinMag. I was using 75gr of Hodgdon H-4895 and found the powder pretty damned close to the top of the case. Now, I have reloaded compressed charges before, but this seemed a bit much (powder level 0.020� below case mouth). Is compressed charges the norm for the 458 Winmag?. I�m using the Hornady 500 gr FMJ RN�s .This is actually for a rifle chambered in 458 Lott, but I haven�t got the dies and brass yet. And I refuse to pay $76.00 for the Hornady stuff. Any help appreciated.

Efryman,
I don't think compressed loads are the norm in the 458 WinMag, not in my experience anyway. I'm loading 69gr of AR2206 (similiar but not identical to IMR3031) behind a 500gr Woodleigh for 2045fps and its certainly not compressed. I'm not familiar with H-4895, could it be the wrong powder for the job you intend?

They are when you are loading that much with that powder...

Have you tried tapping-down the powder before seating the bullet?

Wasn't aware that there was a load for the .458 that wasn't compressed in any bullet weight. That's why the Lott was invented. You can probably load Lott cases in std 458 dies but don't know for sure. Might be a .38/.357 thing.

I worked up to 71.0 grains of IMR 3031 in a Whitworth Mark X 458 WinMag (24" factory barrel) and got 500 grain Hornady RNSP's and FMJ's to go 2100 to 2150 fps with no problems. Start about 5 grains lower and work up as usual.

Eric,

When I was loading for the 458 lott, loads were compressed. I used a 12" drop tube that helped somewhat, but still had compression with the 500 gr bullets.

As far as 458 lott brass and dies, when I had my lott, I used RCBS 458 win mag dies, and re-formed 416 rem mag brass. I'd suggest getting some Hornady belted basic brass, set the sizer .30" off the shelholder, run the cases through, then trim to 2.80"

You might want to check CH4D for lott dies, and they will sell just the sizer, if you want to use your win mag seater.

Yep, you can reload Lott cases with the Win Mag dies, and yeah, even with the Lott you're going to be looking at compressed charges.

Use a long drop tube, and tap the cases a lott (couldn't resist). It will help.

Hornady is now selling real Lott dies for a normal price. I can't tell any difference over using the Win Mag dies though-- but I'm new to belted magnum cartridge reloading, so take that with a grain of salt.

And one more thing: If H-4895 fills the case, don't even think about trying IMR-4320. You won't get anywhere near the same velocity with the same volume of powder.

Pertinax

It gives me great pleasure to resurrect an old post...

Anyway, I've been hearing about compressing charges a lot and was wondering how deeply a typical 500gr bullet would be seated given a standard spec chamber.

Would it make any sense, if you're having a 458 WinMag built, to have it chambered a little longer so you can seat the bullet further out? Can't we just have a custom chamber set up so that a 500gr bullet is seated exactly .458" into the case? (If this already how it's done, just slap me and my ignorance)

IMR 3031 works well, at about 70 grains. Reloader 7 and 15 also work well. Possibly the best powder for the .458 Win was an Accurate Arms suplus powder AA2200 which will push a 500 grain Hornady bullet at just over 2200 fps from my 25" bbl .458 Win.

I understand that the 2200 is gone from Accurate, but there may well be some in the channel. AA provides a data sheet.

In most cases the powder charge will best be placed in the .458 Win case with a drop tube.

Another excellent option is Barnes 400X bullets--if your rifle shoots these accurately you will achieve both speed (~2400 FPS) and penetration. See Rifle #208 on the .458 Win as a back up rifle.

Best Regards,
Fish

reloader 7...

don't look back

jeffe

What about setting up the chamber a litlte longer than standard spec? Is the standard already as long as you can safely make it? And if not, would .458" seating depth be prudent?

Reason for all this chamber talk is that because I want a LEFTY bolt action I will probably have to go the custom route. Might as well specify some other changes, as long as those changes make sense.

As for RL-7, the Alliant website showed a 400gr bullet going 2555fps with that powder. Sounds pretty bad-ass.

I was just loading up some .450 Marlin-equivalent loads in .458 WM (Hornady 350s at 2100 fps) with IMR 3031, and was surprised to find that 64 grains filled the case almost to the base of the bullet. Made me wonder what loading 500-grain bullets to 2100 fps would be like...