What are the options for converting a Winchester Model 70 in .458 WM to another big bore?
I assume going to a .375 HH is easy enough, but what about .416 rem, .416 Rigby or .404 Jeff?
Thanks

What about a 458 Lott? Or 458 Ackley?

Lott is a bit of a thumper for my poor old shoulder. I find the 416 Rigby a hard push as is the .404 Jeff. I have no experience with the 416 Rem

just reload it to the bullet weight / recoil you want .. 300 gr barnes on up

416 rem would work
416 rigby won't feed -- ask the win custom shoppe
404 would also work, but it would be a PITA

Assuming it is a post 64, all actions are long H&H length; pick a belted caliber you like.

quote:

just reload it to the bullet weight / recoil you want .. 300 gr barnes on up.

This…

Or leave it and do about anything with it.

quote:

Originally posted by dogcat:
Lott is a bit of a thumper for my poor old shoulder. I find the 416 Rigby a hard push as is the .404 Jeff. I have no experience with the 416 Rem

Not sure why you were suggesting maybe a 416 Rigby or 404 Jeff in your first post then intimate their recoil is likely too much for your shoulder.
The advantage with the 404 Jeff is that some factory loads are at or close to the original lower velocity specifications than others that are running velocities equal to the 416's.
The original lower velocity loadings of the 404 Jeff cartridge still provided perfect performance on big and dangerous game from easy carrying and shooting light rifles.

Converting to a 416 Ruger would probably be minimal modification.
And as mentioned, if the conversion is about recoil reduction, there are many lighter weight bullets that would still perform excellent in the 458 Winchester. Even at less than maximum velocity.

415 Taylor.

416 or 375 Ruger

I have a M70 in 416 Remington and use it for everything. The conversion would be easy and ammo is cheaper and easier to find than the Rigby or 404.

If recoil is an issue, then why not go to 375 H&H. It will kill anything and is a great all around cartridge as well.

I turned mine into a Lott that was easy enough and very versatile able to shoot both loads (cz 550) no work on action needed. But lots of recoil. .375 seems smart. Unless work needs to be done for longer case then I would go with Ruger or some type of shirt case length caliber

The 458 Lott would be the easiest and cheapest just rechamber the existing barrel.

.375 H&H Mag., .416 Rem. Mag. or .458 Lott would be the easiest, with the latter even doable with the same barrel.

quote:

Originally posted by dogcat:
What are the options for converting a Winchester Model 70 in .458 WM to another big bore?
I assume going to a .375 HH is easy enough, but what about .416 rem, .416 Rigby or .404 Jeff?
Thanks

I have a standard length, magnum bolt face, stainless New Haven M70 that is converted to 375 H&H. Your experiences may differ.

But, mine has the ejector & bolt stop shortened to accommodate the longer H&H cartridge length.
Also the magazine spacer was removed to accommodate the longer cartridge, and the follower replaced with a longer one.

quote:

Originally posted by bluefish:
Or leave it and do about anything with it.

Well… yes. Maybe a little boring is all. We rifle loonies have to have our interesting projects.

416 or 3754 Ruger as 458 suggested..It only makes since these days.

Maybe sell your gun and buy a new Ruger. Project changes always seem to cost more than ya figured on and in many cases don't work so well..

quote:

Originally posted by 458Win:
416 or 375 Ruger

Pretty hard to beat the .458 WM with 450gr CEB solids and the 420 gr Raptors.

AA-2230 gets easily to 2250 fps with the solid and > with Raptor. Both to the same POI.

The 4-5-8 might not be the coolest caliber but it just works for the big stuff. The 350 TSX turns the 458 WM into a flat shooter out to about 250 yards. It is a hammer on thin skinned animals at 2500 fps.

Mark

Ross, if you're not opposed to a rebarrel, the 338 Win Mag case is similar and should work.

Leave it as is.

Or a 300H&H, or better yet a 400H&H.

Done!

Buy a set of dies and you have everything from 45-70 on up. I always thought factory 458 felt like a 12ga with slugs. Load some 300grs and it's a kitten.

Or rebarrel to 338WM or 7 Rem Mag.

My thought is to build a 416 Taylor.
If you shot the rifle in 458 WinMag then you already have the brass. A minor rebarrel and you are on the way.

quote:

Originally posted by WVFred:
I have a M70 in 416 Remington and use it for everything. The conversion would be easy and ammo is cheaper and easier to find than the Rigby or 404.

A 416 REM can be easily downloaded to 404 velocities and cases and bullets are easy to find.

Nothng beats the Lott for killing big ugly stuff IMO, if one can handle the recoil and you can still shoot std 458 Win ammo in it...You can rechamber a 458 win to a Lott with your fingernail! save all that money to learn to handle its recoil..PLus its cheaper to shoot and find or make brass, and bullets galore are available as any bullets and components in these trying times..

If you’re up for a full wildcat conversion consider a 460 G&A. It’ll easily achieve 458 Lott ballistics and get very close to the 450 Rigby. Works in several M-70 magnum bolt faces I’ve tried without modification. Removing the magazine block to allow 3.6” COAL, 375 H&H follower & mag spring, and a modified or replaced 375H&H-length bolt stop would make it work.

Easier to just remove the magazine block, change out the bolt stop and load the 458 WM with AA-2230 to a longer COAL will get you very close or to 458 Lott ballistics.

Or better than the Lott! My CZ 550 in .458 Win Mag had the Saami throat that allows long seating of any long bullets. The 500gr Barnes TSX could be crimped in the botton cannelure for a 3.78" COL, which wasn't possible for the Lott with a Saami throat limited to 3.6" COL. Same in my current Ruger No.1H in .458 Win Mag. It's very easy to load it to Lott ballistics or moreso if wanted.

Even some of the "standard" 500s: the 500gr Speer AGS and 500gr Hornady DGX will exceed 2300 fps using several powders, including H4895, A2230 and 2460. At standard COL of 3.34", those powders plus H335 will easily make 2200 fps. If loaded to Lott psi (62,500 vs 60,000 for the Win Mag) you can expect more than 2200 fps at 3.34" COL from a good 24" barrel. Hornady grants an advantage to the Lott of 50 fps with equal length barrels, but no word on psi.

Bob
www.bigbores.ca

The .416 Rem. Mag is a great cartridge (my favorite go to actually). A lot less recoil than either the .458 WM or .458 Lott (I have both), but it will do it all.

470 Capstick ?

Rebarreling to a smaller caliber is likely to leave a gap around the barrel in your stock.

Why not just load your 458 WM to match your recoil tolerance? For local hunting there are plenty of lighter options to consider. You can load to 45/70 levels on up.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This!

Bob
www.bigbores.ca

IF RECOIL IS A PROBLEM THEN MANY OF THESE POSTS ARE INVALID AS STATED IN YOUR ORIGINAL POST!

Based on that, we need to know what the gun is destined to be used for. DG suggests a 416 Rem as the most practical, still a bit of recoil, but if one can handle a 375 then they can probably handle a 416 Rem..If not DG then a 300 win mag or 338 Win is a good choice, and the 300 H&H or 9.3x62 is always a nice choice..Lots of practical options and a world of BS..

I went through the same issue when I decided that 375 H&H was marginal for Cape buffalo. In standard length actions 416 Ruger is the best choice. Very little magazine and rail work is needed, maybe none from 458. I used a magnum bolt face standard Mauser that was a 300 Win.

There's obvious prejudice here against the .458, but as it has been mentioned several times, IF you're a handloader then use a bullet like the 404gr Shock Hammer (BC = .419) at somewhere between 2350 to 2600 fps, or the 350 TSX from 2500 to 2750 fps, all doable within specs from a 24". Lots of bullets and powders available for downloads to "hot" loads. In fact the .458 Win Mag is one of the most versatile cartridges extant. It's NOT boring! It has yet to be explored to its full potential by even RIP. I've tested loads from the 250gr Hor MonoFlex to the 600gr Barnes Original, and I'm a long ways from done... and will never catch up with RIP!

Bob
www.bigbores.ca

CEB Bullets.

If you want to simply get away from the current chambering and have less recoil, going to a 416 Remington would be an excellent choice. Loaded to around 2,300-2,400 with 400 grain bullets, the recoil is a lot closer to a 375 than to a 458. And it’s a fantastic DG cartridge.

The fellow who sold you the 300 H&H components is a fantastic rifle builder and custom hand loader. He’d be worth talking to if you decide to rebarrel. He’s re-built several model 70’s for me and they all shoot great, like .335” groups from my .264 he re-built. I’m about to take delivery on a .375 H&H he’s finishing up for me and I expect it’ll shoot to about .5” based on what my experience with him has been.

How about 411KDF, 458 case