All right guys, I think this is right

watts = 2.85
lott = 2.8
win = 2.5

So it is possible to shoot in the Watts both the Lott and Win. round, and in the Lott the Win round. BUT, and here is my question......What does this do to the rifle, is it all right? I would think that the neck and throat might get eroded by the powder buring there, but how badly and quickly?

I am asking because I wonder, if you have a rifle chambered for the Watts, but are shooting factory lott ammo, how is this going to effect the gun?

AND (sorry, one more question) I see that a lot of people recommend chambering their Lott with a 2.85", which would then be the Watts right? So where do you find the brass to make the Watts from? I hear that there is 2.85 Lott stamped brass, but don't know where I would find it.

I ask all this because I have a 458 winchester being worked on, and I think that it is going to come back as a 2.85 chambered Lott, but am curious about all this, and maybe whether I should have the barrel stamped 458 Watts?

Thanks guys.

Red

watts = 2.85 yes
lott = 2.8 yes
win = 2.5 yes

So it is possible to shoot in the Watts both the Lott and Win. round, yes

and in the Lott the Win round. yes

BUT, and here is my question......What does this do to the rifle, is it all right?

Prolonged shooting of shorter cased rounds will produce fouling and possibly erosion at the front of the case. When this becomes sufficiently severe, the longer rounds will no longer be able to be loaded into the chamber. It is advised to only use 458 win mag ammo in a Lott under emergency situations, or otherwise limited use.

The reasoning behind the recomendation of the Watts chamber is that as I recall, in Africa, there is factory ammo loaded to 2.85", so you might as well have the longer chamber when going over there to hunt, just in case.

At the time the Lott was developed, full length basic belted brass was hard to come by, so Jack developed a round to use blown out 375 H&H brass, which came out shorter, so he trimmed it back to 2.80". With many sources of belted basic brass on the market, no reason not to go with the longer chamber, and longer brass.

Chamber it 2.85, and shoot Lotts in it.Leaves room for case lenthening with repeated firings, so you don't have to trim.That .050 differemce is only the thickness of a tablet
back.I chamber my long wildcats .050 and more longer anyway for that reason.Ed.

Thanks guys. that was what the smith had said, chamber it .5 over for expansion.

Does anybody ever use metric nomenclature for the 458 Lott labeling? What would it be?

I think if it is decided that it come back a Lott I will just sell off all the ammo and brass that I had for the 458 Win.

Red

Red--It is not .5(1/2 an inch) but .050(1/20 of an inch).
Yes if it comes back as Lott you will be happy with the
power.ED.

Jack Lott made a special reamer for the 458 Lott that does not contain a belt cutter. This way he could go in as far as he liked on an existing 458 win chamber without effecting the headspace. That would be the way to go.-Rob

That is what I meant, the difference between .80 and .85 of course would be .05. I am not thinking clearly today. I need more sleep and a new shooting range (mine got shutdown, sniffle).

I too think I will be muy happy with the extra power. I find it amazing that .3 could make such a difference, but even if it allows the shooting of bullets at the same velocities but at lower pressure it is a bonus. :-)

I am excited. It is a long term project, still getting metal work, then engraving and bluing, then stock. So probably a good 18 months, but I stay excited so it is fantastic.

Red

On my first 458 Lott, my favorite loads were 350 gr hornady or speer's @ 2400-2500 fps, those are 458 win mag level loads, and very accurate using RL-7. The nice thing is you can also load 500's @ 2200+ if you want some recoil ;-)

My Lott is a 2.85".

Jump over to the Wildcats forum and read the 450 Watts thread.

Gotta be careful with interchanging Lott & Watts cartridges, chamber dimensions are at the whim of the gun plumber ordering the reamer. I have a 450 Watts reamer drawing that has a very small diameter for the neck and the straight cylindrical portion between the neck and the throat. Throw in some thick neck wall brass and you will have an instant 100,000 or more PSI and some excitement. Solid monometal bullets can play an interesting game with small diameters of the cylindrical section and short throats. Early Watts chambers had short throats and experienced pressure problems with full house 500 grain bullets.

Brass wall thickness at the neck is all over the place for 458 Lott, Norma basic cylindrical H&H, Hornady basic cylindrical H&H, Barnes basic cylindrical H&H, and others. I have a good selection of all the mentioned cases: Neck thickness runs from 0.009" to 0.014". Sooooo, if your Watts or Long Lott chamber is cut for brass with a 0.010" wall thickness (common) and you push in a cartridge with 0.014" wall thickness, you have gained 0.008" diameter at the neck of a loaded round. As most DGR chambers are around 0.005" or so over the neck diameter of a loaded round (some are less!!), be sure to check with your insurance carrier before pulling the trigger. Your widow will thank you.

Most of the above applies to the 450 Ackley also.

It is a good idea to have the gun builder make up a cartridge gauge with the chamber reamer. This way you can use the gauge to check all loaded rounds. If the loaded round will not go into the gauge easily, then pull the bullet and start over with proper brass.

A little thought on the above will explain some of those pressure problem stories with the Watts, Lott, and Ackley in the hot Zambezi Valley summers. There are no standards for Wildcat cartridges and chambers!!!