Help needed, 458 WinMag bullets refusing to seat straight.

[Northman999]

Hey all, I’m just starting to reload for 458 WinMag, and I’m running into just a crazy frustrating problem where the bullets are not seating straight. I’ve never run into anything this basically ridiculous in 30+ years of reloading. Brass is Winchester, new, sized, bullets are Speer 400 grain. Dies are new Lee. I also tried Lee 45-70 dies to seat, thinking that perhaps the seater plug might be shaped more appropriately for the flat nose bullets, however it made no real difference, and inspecting the seater plugs on both sets of dies they are exactly the same in the 45-70 and in the 458 WinMag.


Here is one bullet partially seated, seriously gross.


Here are four final rounds, a couple of which I disassembled and then resized the brass on and then re-seated the bullets, and they’re still just nasty.

I have tried flaring the case months, which gave a slight improvement only, but still real ugly results.

Any suggestions fellows?

Thanks in advance!

 

[444shooter]

See if you can get a Lee expander die or better yet a Lyman M die.

 

[Potashminer]

My first thought from your pictures - that "ostrich swallowing a tennis ball" look. Do you have a way to measure the inside of your sized cases? I am thinking that your expanding ball is too small for those bullets. For relying on "case tension" to hold the bullets - you want something like .002" or .003" smaller than bullet, at the most. You appear to be crimping the case mouth - Lee Factory Crimp Die? If so, then inside of case mouth just needs to be "slip fit" for bullet, possibly .001" or .002" more tension. Also. even "new" cases often need a chamfer on inside of case mouth, and then have to "flare" that case mouth to seat the bullet. I have been doing okay with the flaring tip in the RCBS 458 Win Mag set, (which looks remarkably like the working end of a Lyman "M" die), but I also have been using the Lyman M die in 9.3mm and .308" with cast gas check bullets. Your concern is well placed!! Bullets seated "crooked" will not "straighten out" when fired!!

 

[Alex McKr]

As already mentioned, slightly chamfering the case mouths will help. As well as flaring the case a little. A Lyman M-die will cure a lot of your problems. Also, try not to seat the bullets in one pass. Bump the bullet to just seat into the case on the first partial stroke. Rotate the case 90 degrees...bump it again. Repeat, until the bullet is firmly seated. Also, firmly guide and support bullet and case with your free hand, as they start up into the bullet seater. Why? Without anything to support and stabilize the 458's long, straight case... aside from the shell holder, the .458 case is prone to 'wobble', as it moves upward into the seating die. Especially with a long, heavy bullet perched on the end of it. Unless gently held in alignment. Very similar in a lot of ways, to the .357 Magnum. Care needs to be taken when bullet seating these, too. Otherwise, the same phenomenon can occur. Which might explain why your bullets are seated crooked.

 

[Longwalker]

Why would you size a new case? It is not necessary. It looks like the case has been reduced in diameter far too much. Besides getting rid of the Lee Size die, the only solution I can see is proper opening up of the too-small case before trying to seat a bullet. The Lyman M die is a good suggestion already mentioned by 444shooter.

 

[reb]

Flaring the case neck, seating all the way to the crimp line and a firm crimp.
The 458 should have a firm crimp regardless of what action.

 

['Boo]

Who annealed those cases?

 

[Peecos]

View attachment 383374View attachment 383375A member on here gave me a heads up about this company, hopefully it’s ok to post their info. They are more for black powder shooting but have what you require, I use these for my 45-70 to seat powder coated cast at .460 They ship direct and are very reasonable.

 

[pacobillie]

Who annealed those cases?

My thought exactly. The cases may be overly soft!

 

[Northman999]

Thanks for all the info guys. The brass came already annealed with dies and the rifle that I bought. The annealing seems to be properly done and it is not overly soft as far as I can tell. I’ve done a fair amount of brass annealing myself over the years, I’m not some expert but I am fairly experienced with it. I went back after reading peoples recommendations and managed to load the rest of a box with better results. I flared the case snacks more aggressively using a 45-70 die made for that, slightly re-lubricated the necks down to where bullets would seat, seated bullets slowly and not all at once, and the crimped firmly. Results seemed pretty good. I’m sure I could’ve at least loaded 50 rounds of .308 win, in the time it took me to load 20 of 458 WinMag, but now I know, and I don’t shoot the big gun that much anyway.

 

[Northman999]

View attachment 383373View attachment 383374View attachment 383375A member on here gave me a heads up about this company, hopefully it’s ok to post their info. They are more for black powder shooting but have what you require, I use these for my 45-70 to seat powder coated cast at .460 They ship direct and are very reasonable.

May look into this if I go cast!

 

[Alex McKr]

I've been loading the .458 for better than two decades, now. I cannot recall ever seeing an outcome like yours. The .458 really isn't any harder to reload than 45-70. So I can understand why an experienced reloader like yourself might find this pretty frustrating.

No need to full length size or anneal new brass. Prior to reloading, pristine brass only needs a little bump with the sizing plug to ensure the case mouth is round...nothing more. Aside from lightly chamfering and flaring the case mouth.

My advice: Pull these loaded cartridges apart. Then, start again with pristine brass. Do not full length size or anneal the cases. Ensure the case mouths are uniformly round. Lightly chamfer and flare the case mouth. Ideally, I like just enough flare so that the bullet will sit upright in the case, unsupported. Take care to guide the case and bullet straight up into the seater die.

Hopefully, your results will be better, next time.

Al

(Edited after seeing your latest post) ps: I strongly recommend getting a Lyman M-die. Should you wish to reload cast bullets...this tool will be a real asset. As well as with jacketed bullets.

 

[Big bore dinosaur]

I found those long bullets need some room in case mouth.
I flared my lott brass deeper,
Ammo turned out nice , no wrinkles,
Lee also makes a crimp die , makes a nice even crimp.

 

[Dogleg]

Does Lee have a proper expander plug in their die set, or just a tapered/ flarng powder-through expanding die? 458 can be a bit of a balancing act between expanding, flaring, bullet type and enough bullet grip; and different bullets and brass respond differently. Bottom line is that if the case is expanded enough you could seat your bullets with a claw hammer and get good results, and if the bullet is doing too much of its own expanding work all bets are off:

 

[Philthy1]

Is the expander straight?

 

[woodchopper]

I have the same bullets Speer 400grn

what are you using for powder? is it a compressed load?

my brass looks the same as yours, same annealing colouration.

 

[bigedp51]

Below the Lyman type "M" expander allows the bullet to be started straight into the case by hand. With jacketed bullets you should only need the bump the case mouth onto the second step. This will open the case mouth approximately .001 larger than bullet diameter and allow the bullet to start straight into the case. You then can crimp the case mouth and close up the wider area if needed.

Below you can see just belling the case mouth will allow the bullet to tilt and start crooked into the case. The type "M" expander allows the bullets to be placed straight into the case by hand and then seated by your die.

Below I have the type "M" expanders for all my pistol calibers and for my .223/5.56 and .308. And they ensure straight inline seating and reduce neck runout. And the type "M" expanders do not work the brass as much as a standard case mouth flare.

45-70 Gov't /458 Win Mag /450 Marlin Expander
https://www.midsouthshooterssupply.com/item/0007699457/45-70-gov%27t-458-win-mag-450-marlin-expander

 

[bigedp51]

Added note, below is a 9mm that was sized with a Lee undersize die, and the case was reduced in diameter .002 to .003 more than a standard die. And the case is wasp waisted and you can see the base of the bullet in the case. And the bullet did not tilt when seated because the type "M" expander was used.

And the seater plug should be a good fit to the bullet shape, this also helps with straight inline seating. And the type "M" expander insures the bullet is started straight in the case mouth.

 

[Northman999]

Does Lee have a proper expander plug in their die set, or just a tapered/ flarng powder-through expanding die?

Yes just the flaring/powder through.

The Lyman M die seems highly recommend by those with experience.

Thanks again all.