hi all,

was talking with a sales rep at winchester today and she said that the action they use on he Classic Safari rifles chambered in .458win was different than the one used on the Classic Safari's in .375 H&H. when i looked at the two rifles side by side in the gunshop, they looked the same and the guy at the shop said they were identical. anybody know who's correct? anybody got one of each.... and if so, have ya ever put the calipahs on em?

thanks!
patrick

[ 10-15-2002, 03:46: Message edited by: ppk1911 ]

The M70 in 458 Win mag has a magazine spacer located in the back on the magazine box. This spacer is installed to shorten the box from approximately 3.6" to approximately 3.350". Obviously, the magazine follower is shortened as well. To convert a M70 in 458 Win mag to 375 H&H you simply change the barrels and installed a factory 375 H&H magazine box and follower. If the rifle fed well as a 458 Win mag, it should feed as a 375 H&H.

Axel

For what it's worth, we make the bottom metal for both and there is no difference except what Axel pointed out. Same receiver and same bolt.

thanks axel and matt-- you guys know where you can get the parts to do the conversion? i'm guessing you get them from winchester as factory replacements?

The size of the ejection port should have been larger on the 375H&H rifle. The receiver bridge normally will have been machined to insure positive ejection of spent brass and loaded cartridges.

Check the rear scope mount base screw holes. They should be different between the two actions.

But yes, they are they same action...

I second BW, the rear bridge must be machined to make the ejection port larger otherwise you will have ejection problems. I have done this to many M70's in converting them to 416 Rem, 458 Lott, etc. If converting say from a 338 MaG, 300 Mag or a 7mm Mag, ya gotta work over the ramp and rails. Good idea to work over the ramp and rails even if it is a 458 as the factory boys don't get it right.

Here is a pic of a M70 300 Win Mag action being milled for 458 Lott:



[ 10-15-2002, 17:48: Message edited by: John Ricks ]

triggerguard1

When did Winchester change the receiver on the 458 so that it is the same as the 375.

Mike

Winchester uses their "standard" length action for the 458, which is the same length as a 30-06. Winchesters uses their "magnum" length for the 375 H&H and 416 Rem. I believe the actions are exxactly the same, except for the width of the rear bridge. So I would have to agree with John Ricks and say that Axel troll and triggergard are WRONG!

Casey

ppk1911,

Don't forget to order a new bolt stop and ejector. These are both a bit shorter than the 458 versions. It's also possible to just modify the original parts.

I did see a parts breakdown, with prices, on Winchesters website. Not sure if it's still there, but you could check.

One last note, the 7mmSTW rifles were built on with the longer ejection port also.

So after all this discussion is it the consensus of opinion that a guy could buy a 458 Mod 70 and with slight receiver modification and rechambering have a 458 Lott?

John Ricks, BW, and Mike375 are right, OF COURSE!

It is significant gunsmithing to convert the 458 WinMag M70 to 458 Lott. Same for a Whitworth Mark X 458.

A CZ 550 Magnum Safari or (cringe) Remington M700 can go directly to 458 Lott by simply rechambering by hand (cringe) with a T-handle.

So for the perfect rifle it is nearly a wash dollar-wise:

Win M70 458WM significantly gunsmithed, as above.
Win M70 375H&H rebarreled and less action work.
CZ 550 458WM rechambered and 3-position safety.

Except that With the CZ 550 you get 5 in the magazine and 1 up the spout, much less dearly. If you want that with an M70, there goes the budget.

BW,

On the stainless M70s I have seen in 7mm Rem and 300 Win, the bolt stop allows the bolt to come back all the way to the rear of the magazine box.

In these Model 70s, the magazine still has the block off in the back of the box for the shorter cartridges but rather than just being a straight bit of metal, it tapers at the top and meets the back of the box. So when a cartridge is in the magazine and the bolt fully back, there is about .25" distance between the bolt and the cartridge the head. I believe this is done to make loading the cartridges into the magazine easier because the rims won't catch on the back of the box.

The 375 bolts come back further and the bolt when fully back will expose about half of the middle screw hole. There is a little ramp between the bolt face and the rear of the magazine which I assume is also to make it easier to put the cartridges in the magazine.

Mike

When I built my 450 Ackley on a pre-64 M70 , I ran into exactly the same cartridge ejection problems John Ricks described above. Milling back the rear bridge wasn't very difficult and completely solved the problem. Properly done, these M70's can be extremely slick feeding and ejecting rifles in this caliber.-Rob

Rob,

The 450 Ackley's COL is longer than 3.6 in. I load my 450 Ackley to around 3.690 in. The internal dimension of the M-70's box is measured at around 3.6 in. How did you get it to fit? Did you have to seat the bullet deeper to accomodate the shorter magazine box? Thanks.

Also, when converting as in the milling of the receiver shown above, the rear of the magazine rails need to be cleaned up and the rear most portion of the magazine opening needs a bit of an angle and some radius & smoothing work. I open up the front of the rail lips and broaden the feed ramp. Everything gets a smooth polish also.

For Mark, yes, the 458 Win Mag action may be converted, with all of the above steps. Takes a milling machine & a good assortment of end mills and a good amount of hand tools (Air die grinders, carbide burrs, grinding points, files, polishing stones, etc.) Also need to work over the bolt face lips and the extractor lips for smooth flawless feeding of the rim up into the bolt face. Best to install a new Precise Metalsmithing extractor.

I grind back the original "standard length" bolt stop and ejector, this way I can tune the action timing for snappy ejection of cases and loaded cartridges. Some of the factory "375 H&H length" ejectors are too short and you get "lazy" ejection.

For the ultimate, install a wider Blackburn box, this reduces the cartridge stack angle and improves both feeding and reliablilty.

Plus there are several other things I accomplish to the receiver for increases accuracy and dependability.

[ 10-16-2002, 06:46: Message edited by: John Ricks ]

guys, thanks for all the info! i had a chance to measure the ejection port on a new 458win and it was approx 3.380 or so. needless to say it's gonna have to be opened up to handle 375 length (3.600 or so) rounds.

[ 10-22-2002, 10:01: Message edited by: ppk1911 ]