458 win mag 26" barrel velocity.

[Buster95]

I just checked Wikipedia and they mention muzzle velocity of 2,192 ft/s with 500 gr bullets and 2,468 ft/s with 400 gr bullets from a 26" barrel!!! I know Wikipedia is not the best source but I'm curious what velocities you can reach from a 26" barrel?

 

[JimP]

That is a loaded question (pardon the pun.)

That velocity is on the upper end of a 500 grain and 400 grain bullets out of a .458 Win Mag. But you will see velocities all over the place depending on the ammunition manufacture or others that reload for it. Even different rifles will shoot the same loaded ammo at different velocities with the same barrel length, it depends a lot on the pressure of the load. Some rifles will show no pressure signs while others it will be present.

 

[Amon458]

I read somewhere that generally you gain or loose around 150FPS for each inch for these big bores. If this is wrong someone please correct me.

 

[matt85]

amon458, you dont lose/gain that much, its usually closer to 50fps per inch in my experience. however 50fps can make a big difference when your throwing 500+ grains of lead at something.

buster95, i suppose its possible to get 2200fps with a 26 inch barrel but you would need to load the cartridge fairly hot. i believe 2100-2150 would be more of a normal speed with that barrel length. Hornady loads their factory DGX/DGS 458 WM ammunition very hot, in fact most factory 458 WM ammunition ive seen showed pressure signs after being fired.

-matt

 

[Amon458]

matt85 Thanks for the correct info. To the OP I believe you would be better served with a 458Lott or a 460WBY if you are looking for more velocity in a 458cal or just because they are more fun!

 

[Gert Odendaal]

amon458, you dont lose/gain that much, its usually closer to 50fps per inch in my experience. however 50fps can make a big difference when your throwing 500+ grains of lead at something.

buster95, i suppose its possible to get 2200fps with a 26 inch barrel but you would need to load the cartridge fairly hot. i believe 2100-2150 would be more of a normal speed with that barrel length. Hornady loads their factory DGX/DGS 458 WM ammunition very hot, in fact most factory 458 WM ammunition ive seen showed pressure signs after being fired.
-matt

Members something I got as an answer from Terry Irwin former PH/Gameranger in Tanzania regarding a .458 Mannlicher Schoenauer and a 26 " barrel and performances...

Hi Gert
I had a custom (to my measurements) .458 built by Mannlicher Schoenauer. I had an "gost ring" aperture (peet) sight fitted on the back of the bolt. The reason I bought this rifle was because I had many problems with magazine base plates opening or rounds being ejected from the top if you flicked the bolt open fast. The Mannlicher's revolving magazine controlled each round and fed from it smoothly. In fact it is the smoothest operating action I have used. The flat bolt took a bit of getting used to but in the end I mastered it.

When I ordered my rifle I stipulated the standard 24 inch barrel. They refused to do this and insisted on a 26 inch barrel. They said you could not get the correct balistics from the .458 with a shorter barrel. This may be the reason that I never experienced all the faults that others did with power and penetration. My .458 had more penetration than my .375 with solid bullets.

I don't think you can go wrong with your Mannlicher. I shot over 1000 elephant with mine. I did not like the newer model Steyr- Mannlicher with the plastic box magazine.

I hope this answers your questions.

Terry

 

[Buster95]

Thanks for the replies

 

[Stuey]

Hi Buster
I was getting 2200fps out of a 25 inch barrel with 480 grain Woodliegh bullets.
These were the ones with the special cannula suited to the Win Mag 458.
From memory i was running 74 grains of reasonably fast powder (ADI 2206H) and Federal Mag primers, Winchester brass. Used the Winchester brass because it is thinner than the likes of Norma and thus allowed a little more volume.
I had mild compression with the loads and set with a crimp.
Brained a big bull ele and a cow ele with this load, insurance shots taken but not really required. Dug one bullet out from the shoulder of the bull and it had traveled at least 1500mm before coming to rest on the shoulder blade.
I sold this rifle recently due to another project. I really rate the .458 but if i were to do it again i would buy a Lott and just down load it to a get a compromise between recoil and killing power / penetration.
Cheers Stu

 

[Buster95]

The 458 Lott seems a better choice, more versatile, no compression.

 

[Stuey]

Agreed.

 

[BWH]

@pheonixphil is super F'n smart at that stuff.... He has a .458. If anyone can give you a good answer.... It's him.

 

[bpcr]

This week I reloaded some .458 Hornady interlocks W/a hi of 2219fps. And a low of 2199 fps. Average was 2211 fps. from a CZ 550 Safari Magnum W/25" barrel in .458 Win Mag. There were no pressure signs and it was once fired brass. Group size at 62 yards was 2.5" vertical W/ one flier to the left which made it 3" . My fault I pulled. Used a Lab Radar chronograph and reloaded outside the box.

 

[matt85]

what was the outside temp? that's a very hot load for a 458 WM so you do run the risk of pressure spikes in high temps.

do remember that speed isn't as important as accuracy when it comes to a 500gr .458" bullet. given the bullets high SD, as long as your over 2000fps its going to do fine on game at standard DG hunting ranges. my 450/400 NE 3" only got 2030fps with a 400gr bullet and that would do all the big 7 within reasonable ranges.

-matt

 

[Daga Boy]

I agree with Matt's advice.
A lot of the issues we here about 458s not doing what they are supposed to has to do wit taking shots which are too long for the calibre (a result of using a scope)
That having been said it us possible to get higher than normal performance out of 602S as most will accomodate a COL about half way between a standard 458wm and a Lott