458 Win to 458 Lott conversion

[M70375!]

Hey Guys,
I am thinking about getting a model 70 458 Win mag and converting it to a 458 Lott, the Lott is a longer cartridge , so would I also have to have the magazine box made longer. Will the Lott chambering shoot the 458 win cartridges as accurately as a standard 458 win would shoot them.
Thanks Guys

 

[Wyatt Smith]

You should be able to get a 416 rem mag box and bolt stop. I doubt that’s all that will be required to make It feed 100%.

 

[Hunter4752001]

Consult a good gunsmith about your rifle. While the barrel work is easy, and the mag work may be doable, the question is whether the action length is sufficient without removing metal (not a question I can answer).

 

[Mekaniks]

Here is a previous thread about it...

H

Thread 'Rechambering Model 70 Safari Express in .458 Win Mag to .458 Lott'

Jul 19, 2021

What all would need to be done to rechamber a Model 70 Safari Express in .458 Win Mag to .458 Lott? Would it just be cutting the chamber to fit the Lott, or would the magazine well need to be opened up as well?

The .416 Rem Mag and .375 H&H both fit in the same action, so I'd think it'd just need the chamber opened up. I'd like to hear from anyone who has had this done, along with some gunsmiths they'd recommend to do the work.

• hammz
• Replies: 82
• Forum: Firearms & ammunition

 

[ftrovato]

Hey Guys,
I am thinking about getting a model 70 458 Win mag and converting it to a 458 Lott, the Lott is a longer cartridge , so would I also have to have the magazine box made longer. Will the Lott chambering shoot the 458 win cartridges as accurately as a standard 458 win would shoot them.
Thanks Guys

Can't you come up with a modern powder that will enable a Win Mag to approach Lott velocities?

For me, It's more about the bullet tip than velocity in big bores. I think the Win Mag will get it done all day long with the right bullets... Just my two cents to save you some money. Good luck what ever way you decide to go.

 

[BeeMaa]

Can't you come up with a modern powder that will enable a Win Mag to approach Lott velocities?

For me, It's more about the bullet tip than velocity in big bores. I think the Win Mag will get it done all day long with the right bullets... Just my two cents to save you some money. Good luck what ever way you decide to go.

The larger case of the LOTT allows for lower pressures for the same speed and bullet weight. Plus the extra length allows for heavier bullets that increase the sectional density and can keep it moving at 2200-2300 fps.

In reality, the LOTT is everything that the WM promised it would be and failed to deliver.

 

[Luvthunt]

The larger case of the LOTT allows for lower pressures for the same speed and bullet weight. Plus the extra length allows for heavier bullets that increase the sectional density and can keep it moving at 2200-2300 fps.

In reality, the LOTT is everything that the WM promised it would be and failed to deliver.

While Bee May is right on But if you accept that a 480/500 gr bullet at 2150 fps + will get the job done the 458 Win will do all.
By the way that was the bullet and velocity that was achieved in 1897/98 that ended the black powder era with 4 &8 bore rifles.

 

[zephyr]

The new Win Mod 70 Safari Express rifles, 375 H&H 416Rem and 458Win mag are all built on the same Long Action.. I did the same as you are asking, re-chambered a 458 win mag to a 458 Lott. ...Besides the re-chambering all that was needed was to remove the Magazine Block or spacer and to shorten the ejector