.458 Win Mag light load questions

[DEF23]

So, I am getting ready to load up a few hundred rounds for my .458 and had some questions about powder charges and fillers in light loads (under 1200fps).

My full powered loads are 500gr jacketed Hornadys over some RE10x, but I also have on hand some 480gr cast lead with some gas checks and was wanting to try out some loads I found in my Lyman Reloading Handbook (46th edition) --- namely 17-to-21 grs of Unique (1200-1300fps) OR 24-to-30 grs of 2400 (1200-1400 fps.).

I am just worried about whether or not I need to worry about having a Dacron wad as a filler in there ??

The Lyman manuel states it as needed for .45-70, .50-70, ect. But it has no mention of it at all in the .458 section !!?? I am assuming since all three of those cartridges are so close in size that it would be needed in all three of them.

I have never reloaded any light loads before and thus have never used any fillers (except using COW for fire-forming .300 Win Mags to .458) previously. And to be honest here, I am a little hesitant to do so after reading some of the issues that other people have had in the past (ringed chambers, barrels, ect.).

I also don't want to deal with having light loads that are good only for the range and have position sensitivity issues. I am trying to find some light loads that my family & friends can shoot and yet are still reliable enough to have bouncing around in my truck for months at a time and go off when & like they are supposed to.

I would appreicate any tips, info or suggestions about the above.

[Stephen Cohen]

I would be interested in the answer to your questions as well. I hate recoil, old bones and nerve damage, I have used a 535 gr cast and from 40 to 45 grains of H4198 and they were mild enough, no idea of velocity but it was better than 1400 I am sure. I also have tried a 460 gr cast with same loads for much the same results. I use CCI mag primers for all loads, I have also found a reasonable crimp is needed for a good burn.

[Nobade]

A case full of Trailboss works well also and will give about 1200 fps. Just fill it up to the base of the boolit with no compression.

-Nobade

[Fritz D]

I can't answer your question re fillers . . . but I've had good success in a .458 Win. Mag, using TrailBoss and a 385 grain cast boolit. Like the post above, filling the case to the base of the bullet (22.3 grs in my cases) gives just slightly better than 1200fps. Accuracy is 2-1/2" - 3" at 75 yards. Recoil is very light.

[94Doug]

Unique or 2400 are going to be fine without fillers.

Doug

[Larry Gibson]

As mentioned with Unique using that weight cast bullet a filler will not be necessary at 1200 fps.

Larry Gibson

[highpower]

Have shot thousands (literately) of .458's loaded with Unique without filler, no issues!

[DEF23]

Thanks guys --- excellent to know about not needing the filler. I believe that it will make for a much more 'in-the-field', reliable load. I will get some ready tonight, so that I can test them when I go the range on Sunday.

[Bill*B]

I believe it was one of the forum members who mentioned using potato fiber packing peanuts (from Office Depot) as a filler. I tried it and it works great - although it is a bit weird to see the packing peanut blow out and waft away downrange. I've found SR 4759 - with or without filler - is a great reduced load .458 powder.

Don't despair! My .458 Magnum is the most accurate rifle that I own. I confess that I shoot my 7.62 X 51 and .30-30 rifles more, but the big .458 will better both of them by a minute of angle, or more. Bill

[DEF23]

I just happen to have a some Unique and some 2400 on hand that I was willing to try out. There really isn't a great powder selection anywhere locally for me. The closest powder in-stock for me is a two hour drive and extremely limited at that.

And after hearing so much about fillers (both good & bad) and having very little to no experience in using them --- I figured that I'd rather give it a go without using them. It seems as if it would make a more reliable in-the-field load.

Now, if any of you gentelman with some .458 light-load experience could comment on how much crimp is needed with these light-load --- I'd be greatly appreciative.

Thanks in advance, guys.

[highpower]

DEF23 - As to crimp, very light to none. Just enough to remove case bell and maybe a touch more. These type of loads don't recoil enough to worry about bullet set-back. Just crimp enough to that they function thru the rifle with no bullet set-back ( when bullet hits feed ramp).

[DEF23]

Thanks guys. I loaded up some this morning and took it up the hill with me when I did some other range testing. I didn't bench-rest them for accuracy yet but everything went just fine.

I ended up using 19 gr. of Unique, Win. Mag primer and a light crimp (1/3 turn Lee FCD). I set my o.a.l. at 3.340" but it turned out to be just a tad too long for my Ruger M77 magazine box. So, I'll set it back just a little bit, make up a few more and then start trying it out for accuracy next trip out to my range.

Definitely feels like a cream-puff load though --- something along the lines of my Ruger .44 Deerstalker or my Rossi 92' in .357. I was also function testing & bench-resting a freshly built (by me) DPMS LR-243 and it definately had more kick (& noise) than the .458 did.......LOL !!!

Now, I just need to whip up 50 more for plinking ammo and then get to work on my full powered .458 loads (50 Hor. SP's & 50 Hor. FMJ's over some Re10X) for the more serious work.

Thanks for all the help, guys.