.458 win mag for North America

[camerl2009]

I’m doing some load development for the .458 win mag.

I’m using 350gr hornady round nose with accurate 2015(only powder that I could find locally).

Loaded in groups of 3 so far I’m going to try 67.5(starting load from Hodgdon and a few other sources) and 69gr.

Loaded these with a lee loader I scored a while back.

 

[Northern Shooter]

I picked up a 458 earlier this year and it has become my favourite firearm.

It's a very versatile big game round that works on all north American big game from White Tail to Brown Bear, Moose and Bison.

I don't reload so I only have access to 400gr, 450gr and 500gr loadings.

Reloading opens you up to 300gr, 325gr and 350gr loads making it even more versatile.

I'm curious to know what velocities your getting with those lighter loads?

 

[mdwest]

Load to 45-70 velocities with a 350 gr projectile and you’ve got ballistics equivalent to what’s been used to take bison, moose, and brown bear for a hundred fifty years…

 

[camerl2009]

I picked up a 458 earlier this year and it has become my favourite firearm.

It's a very versatile big game round that works on all north American big game from White Tail to Brown Bear, Moose and Bison.

I don't reload so I only have access to 400gr, 450gr and 500gr loadings.

Reloading opens you up to 300gr, 325gr and 350gr loads making it even more versatile.

I'm curious to know what velocities your getting with those lighter loads?

Starting data(67.5gr) says 2250fps from a 22 inch barrel. With that load I calculated just 3 inches of drop at 150 yards. Hopefully I can get out for spring black bear with this.

And you should really look into reloading. currently I’m using brass and bullets I got cheap but with those 350gr round nose hornady bullets I’m looking at $2.19 vs the federal trophy bonded bear claw at $9.45 a round.

I’d love to go after moose and bison but unfortunately moose tags are not easy to come by in Ontario. theirs no bison here other then the farm out in my county and don’t think they would like me bringing the win mag out there lol.

 

[camerl2009]

Load to 45-70 velocities with a 350 gr projectile and you’ve got ballistics equivalent to what’s been used to take bison, moose, and brown bear for a hundred fifty years…

The starting load is 2250fps from a 22 inch barrel and pretty flat shooting out to 150 yards and at that range you are close to the minimum recommended velocity for the hornady bullet.

I am going to play around possibly with some campro plated and maybe .45 acp/.308/.30-06 casings as jackets for bullets.
Biggest issue I have is I need a chronograph.

 

[Ridge Runner]

Just my 2 cents, from my very limited testing experience.

First you'll need to check with Hornady and any other bullet companies as to their minimum and maximum velocities for their bullet(s), and their respective optimum velocity.

Since your firearm is a 458WM you have the option to use the longer 458WM bullets, or the shorter 45-70 bullets if you choose.

Second, you'll need a powder that is listed for use in both calibers 45-70 and 458WM, and for use in the same bullet weight; ie RL7, 350 gr bullet.
NOTE: I used the Marlin 45-70 Gov load data. When I was experimenting.

Notice the maximum grain powder load for the 45-70 and the minimum grain powder load for the 458WM.

Notice their is a significant unlisted grain powder load data.

Very Important Safety Note: The Pressures of both calibers you need to stay within.

 Now while staying within the parameters of the 45-70 bullet velocity range, and within the pressure range of both the 45-70 and the 458WM there is the opportunity to develop a 45-70 "maximum/magnum/+P/etc" load, and/or a safe, very light, very manageable 458WM load using the shorter 45-70 bullet rather than the longer 458WM bullet.

Good luck with your testing and let us know what you ended up with as a "pet load".

 

[camerl2009]

Just my 2 cents, from my very limited testing experience.

First you'll need to check with Hornady and any other bullet companies as to their minimum and maximum velocities for their bullet(s), and their respective optimum velocity.

Since your firearm is a 458WM you have the option to use the longer 458WM bullets, or the shorter 45-70 bullets if you choose.

Second, you'll need a powder that is listed for use in both calibers 45-70 and 458WM, and for use in the same bullet weight; ie RL7, 350 gr bullet.
NOTE: I used the Marlin 45-70 Gov load data. When I was experimenting.

Notice the maximum grain powder load for the 45-70 and the minimum grain powder load for the 458WM.

Notice their is a significant unlisted grain powder load data.

Very Important Safety Note: The Pressures of both calibers you need to stay within.

 Now while staying within the parameters of the 45-70 bullet velocity range, and within the pressure range of both the 45-70 and the 458WM there is the opportunity to develop a 45-70 "maximum/magnum/+P/etc" load, and/or a safe, very light, very manageable 458WM load using the shorter 45-70 bullet rather than the longer 458WM bullet.

Good luck with your testing and let us know what you ended up with as a "pet load".

Biggest issue is finding powder even though a lot of Hodgdon lineup is made here in Canada it has to be shipped to the states packaged and then distributed out. Alliant powders are nowhere to be found up here my LGS has a 5lb keg of reloader 7 but I do not feel like spending that kinda money on it.

 

[WoodencrossIII]

This is great as I was just inquiring yesterday how my 458 Lott would work for shooting plains game. I was looking at some Barnes 250 gr TSX or even 300gr. For shooting deer here in Missouri where I live shots can be out there a bit. Killed a buck at 230 yards this year, so I was wondering about using my Lott as I love the rifle and want to hunt with it. I don’t see why I can’t make those longer shots with lighter bullets but lighter they are the more energy they shed but even a good 350 gr would carry down range.

 

[camerl2009]

This is great as I was just inquiring yesterday how my 458 Lott would work for shooting plains game. I was looking at some Barnes 250 gr TSX or even 300gr. For shooting deer here in Missouri where I live shots can be out there a bit. Killed a buck at 230 yards this year, so I was wondering about using my Lott as I love the rifle and want to hunt with it. I don’t see why I can’t make those longer shots with lighter bullets but lighter they are the more energy they shed but even a good 350 gr would carry down range.

I can bet that the Lott would be flatter shooting. My rifle(Ruger tang safety) came with a scope but I do not know if it will take the recoil. I calculated it out and should be around 42 or so ftlbs of recoil.

 

[camerl2009]

Something I have wanted to try is 3 .45 caliber round balls like some guys load in .45-70 I will have to figure out a Hodgdon powder I can use to do that.

 

[Ridge Runner]

Biggest issue is finding powder even though a lot of Hodgdon lineup is made here in Canada it has to be shipped to the states packaged and then distributed out. Alliant powders are nowhere to be found up here my LGS has a 5lb keg of reloader 7 but I do not feel like spending that kinda money on it.

That's sad that powders made in one's own country can't be first distributed to its citizens.

I just used 350 gr bullet and RL7 as one example. Check the reloading manuals and/or online reloading data there should be some other compatible cross 45-70 and 458WM bullet/powders that might be more available to you folks up north.

 

[camerl2009]

That's sad that powders made in one's own country can't be first distributed to its citizens.

I just used 350 gr bullet and RL7 as one example. Check the reloading manuals and/or online reloading data there should be some other compatible cross 45-70 and 458WM bullet/powders that might be more available to you folks up north.

Every once in a while we will get OEM grade versions of some powders. All I have on hand is IMR4064 and the accurate 2015 currently. Always on the look out for 4198 and 4895 but it’s thin on the ground. I found some large rifle primers finally after 2 years of looking.

 

[Ridge Runner]

Every once in a while we will get OEM grade versions of some powders. All I have on hand is IMR4064 and the accurate 2015 currently. Always on the look out for 4198 and 4895 but it’s thin on the ground. I found some large rifle primers finally after 2 years of looking.

Check out my previous OP dtd Aug 23:

Down loading the 458WM to 45-70 loads.

I'll have to refer back to it myself. I believe one of the test loads I used IMR4064 as it is a common powder for several of the calibers I reload.

My 458WM prefers H335 with 500 grain bullets.

 

[camerl2009]

Check out my previous OP dtd Aug 23:

Down loading the 458WM to 45-70 loads.

I'll have to refer back to it myself. I believe one of the test loads I used IMR4064 as it is a common powder for several of the calibers I reload.

My 458WM prefers H335 with 500 grain bullets.

Interesting read for sure. I do find it funny that most people think anything but a cup and core would be needed for black bear a .30-30 would definitely do the job out to 150 yards. Only reason I’m going with the .458 is my .303 has a couple issues and I haven’t set up to load for the snider yet(next rifle to take black bear with).

 

[camerl2009]

Eventually I’m going to get a mold for this as well. 485gr or so in lead and I’m going to get a steel/iron mold that way I can try zinc. Zinc bullet the same length as the 485gr would be around 300gr.

 

[CoElkHunter]

I've been reloading Barnes 450gr. TSX with 70.0gr. of H335 and Speer 350gr. Hot Cor with 77.0gr. of H335 in my .458WM. Both loads "feel" a little light, but I too don't have a chronograph, so I don't know.

 

[ChrisG]

I have a box of 350 speer hot cors that I have yet to load into my 458WM. They were designed for 458 velocities, so they should work well around 2300fps and be reasonably flat shooting on big game as well.

I did load some 400 grain Speers as well, but judging from the large amount of lead exposed at the tip, they were designed for the 45-70, but they made real cheap paper punchers in an express rifle and should still work well on black bear. 400 grains is 400 grains. It's still quite a smack, even if it's not suitable for really large animals.

 

[ChrisG]

I've been reloading Barnes 450gr. TSX with 70.0gr. of H335 and Speer 350gr. Hot Cor with 77.0gr. of H335 in my .458WM. Both loads "feel" a little light, but I too don't have a chronograph, so I don't know.

I might steal your load of H335 for the 350 Hot Cor. And I do have a chrono. Maybe I'll load some and shoot them over the chrony.

 

[camerl2009]

77gr of h335 sounds a bit hot. I haven’t used h335 but can’t see to find a load for it on Hodgdon data center for 350gr bullets.

 

[CoElkHunter]

This is from the Hornady manual using THEIR 350gr. bullets: