M70 Lott owner needs help

[kfrye]

Afternoon gentlemen,

I’m finally getting my Model 70 in 458 Lott together and loaded up a few rounds and discovered the mag box and feed ramp aren’t long enough to take a cartridge at 3.600.

I got a round chambered, but it went tight and put a slight land mark on the bullet (Hornady 500 gr FMJ).

For disclosure, this rifle was purchased after New Haven closed during liquidation.

Are there any Lott owners on here that could help with dimensions/ photos?

Im going to check this one against my 375 h&h to curb curiosity, otherwise it looks like it needs to head off to NECG for some work.

Thank you

 

[450 Dakota]

What was it originally?

 

[baxterb]

The mag box still has the block in the back for a standard length magnum? You will at least need an unblocked mag box and maybe a new bolt stop. But really it needs a full inspect.

Who converted it to Lott?

 

[kfrye]

It was born a Lott

 

[Mark A Ouellette]

It was born a Lott

Obviously not with a lot of magazine!

This should not be hard to modify to accept 3.6"+ length cartridges by any competent gunsmith.
The trouble is those are few and far between...

 

[Flipper Dude]

I’ve never heard of a factory 458 Lott in a Model 70. Not that there weren’t, and I haven’t researched it. Just never heard of one. Winchester custom shop I would suppose.

 

[Letzhunt]

I converted a 458 wm to a 458 wm+. This basically allows you to load long as 3.6" just like the Lott. Take a photo of the mag box. If it has a block in the back it was never a Lott. No worries you can get the block out and then you will likely need a new Ejector and bolt stop. If it was a 458 wm you can cut about 0.2" off the bolt stop and swap the ejector to a shorter one. Basically cut the bolt stop at the same angle the same difference the new ejector and old ejector are from each other. I can help with part numbers probably. Let's start with where your Win was made? Serial numbers will help too.
I would also do a dumb round to find the lands/ jam. You may be able to load shorter and help.

 

[baxterb]

Really interesting. And stainless no less! Have never seen one! Never knew they made one and it makes me wonder why they didn't as I would imagine they'd be popular.

Yes, pop out the mag box and send a pic. Buy yeah, if the bullet is jamming the lands at factory OAL - needs a look.

 

[BnC 04]

First thing I would do is fire off an email to Winchester as you may have a "unicorn".
If a Lott slipped out of their custom shop that will be good to know.

 

[Mekaniks]

Are you using handloads or factory Hornady ammo?

 

[Letzhunt]

Very intriguing. barrel markings look to be factor but round is way too long in mag and at ramp. Measure the COAL of that round

 

[BGHNTR416]

Might need a new follower and spring as well??

 

[MRBlack]

A picture of the proof marks on the back of the barrel would indicate if it is a factory 458 Lott barrel (as it certainly appears to be) and it would also show if it were from the custom shop as they have a specific proof mark as well.

 

[cajunchefray]

Interesting example of a Model 70 New Haven. Could be a special Custom Shop build, just not finished.

Some ruminations about the large caliber M70s after having a couple of each, .375 H&H, .416 Rem Mag, and .458 Win Mag.

As you stated you have a M70 .375 H&H mag.

Switch out the magazine box from the .375 to the .458 Lott and see if the cartridge feeds properly for a Single Round. Out of the box and up on the ramp.

The box taper from 375 to 458 is different and it won't feed multiple wider 458 cartridges. This is just to check the mag box length, .458 WM (3.34 OAL) vs. .458 Lott (3.60 OAL).

If so, a H&H length magazine box is needed, BUT the bolt stop and ejector dimensions will need to be modified for the H&H length cartridge.
A .416 Rem Mag magazine box, along with a modified bolt stop, and ejector, as @baxterb mentioned should sort this out.
A good gunsmith, that knows later Model 70s can sort this out.

 

[JHT]

I’ve seen factory Model 70 Lotts but only from the Custom Shop. The last one on Gunbroker was probably 2-3 years ago and brought just over $5k. A quick call to Browning will tell you everything you need to know about the origins of this particular rifle.

 

[Letzhunt]

Sourcing a proper follower may prove difficult as most of the sources are dried up and factory asks for the Ser#. I need one for my converted 458 wm to a longer mag box. I just haven't asked anyone for a number to give Winchester so I can purchase one. I also thought of having one 3D printed...... or 10 or so. If I recall the .375 follower is what you want. My follower works after a stiffer spring was added but it does float a bit in the rear. May be a small aluminum weld and fitting at the rear worse case.

 

[Letzhunt]

Well not aluminum ..... my follower is SS so may be easier to extend. OP keep us posted on what you find. We will get you sorted.
And thanks for getting me going on what I need to finish on my own project. May start a new thread to get some info.