Hi All,

I am considering rechambering my BRNO 602 to 458 Lott from 458 Win Mag, but I read that the rechambering does not necessarily clean out the chamber and you end up with a slight ring aroud fired Lott cases. Is this general the case or just a worst case scenario ?

I have never done it but it would depend on the size of your original chamber and the size of your Lott reamer. But so what? It won't hurt anything.

I don't know if you reload, but with the newer powders there isn't a great need for the Lott. The .458 WM will do anything that the Lott will do, hunting wise.

Best thing is to do a chamber cast and compare dimensions. Because of tolerences in chamber and reamer specs, there is always the chance.

Why ?

Lott got hurt way back in 1959 using the early slow 458W loads with 1959 bullets.

Today's 458W ammo is a whole different ball game, and will take any game in the world.

You can probably buy it in places that have never heard of a 458 Lott.

When Lott was hurt, there was no logical reason for a new 45 caliber big bore. He could have dropped down (LOL) to the 416 Rigby or gone to the 450 Mashburn, Ackley, Watts or Barnes Supreme. So why a new cartridge ?

The 450/400 has long been the standard by which 45 caliber rifles are judged to be able to stop a fight.
The 458W shoots a heavier bullet a tad faster, so why devalue or perhaps screw up your BRNO chasing ONE man's ONE bad experience ?

A 500 gr Barnes Banded solid @2200 fps is certainly a fight stopper.

If the 458WM is great with the new powders those new powders make the Lott even better.

I like the Lott over the WM 'cause it is just more versatile and IF you need or want to both of mine shoot WM pretty well.

I really like the Lott myself.

.

It might be one of those "I want one just because" things and if so, you should go ahead and do it. If you wanted a totally rational, cost/benefit analysis, fact based decision, then you would not be in this hobby at all. Just do it and shoot. That is all that is important.

I appreciate the feedback, all very valuable. My reason for considering the Lott was mainly on two fronts. Due to the magnum length action of the 602 the 458 Win Mag rounds under recoil move forward in the magazine, hence causing loading issues (loading the magazine, then just chambering the rounds works fine as they are all well back), the extra length of the Lott will take up the magazine nicely.

The second reason is, from what I read the Lott will do everything the 458 Win Mag can do at lower pressures, plus you have the advantage of driving them a little harder, if you so desire.

I am no export in any of this, just going on the research I have done.

quote:

Originally posted by dpcd:
It might be one of those "I want one just because" things and if so, you should go ahead and do it. If you wanted a totally rational, cost/benefit analysis, fact based decision, then you would not be in this hobby at all. Just do it and shoot. That is all that is important.

+1.....Tom

quote:

My reason for considering the Lott was mainly on two fronts. Due to the magnum length action of the 602 the 458 Win Mag rounds under recoil move forward in the magazine, hence causing loading issues

Wouldn't a spacer like they do on the M70 control that issue.

Nothing against the Lott if you want one. Just other ways to handle the feeding issue.

Paul, I considered the spacer but that would mean modifying the magazine follower then adding a spacer of some sort to make the magazine more adaptable to the 458 Win Mag cartridge.

Again not knowing what it takes I thought it would be easier to just extend the chamber to Lott, but all good suggestions, thanks again.

quote:

The second reason is, from what I read the Lott will do everything the 458 Win Mag can do at lower pressures, plus you have the advantage of driving them a little harder, if you so desire.

Another exceelent reason. Sounds like you are talked into it.


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I can shoot .458 Winchester Magnum ammunition in my .450 Watts with no difficulty and only a slight loss of accuracy, but on advice from John Buhmiller, I went to a 20" twist, rather than the 14" espoused by Winchester. According to John, the .458 cartridge in the .450 Watts chamber is not nearly as accurate with the faster twist.

I have the fallback option of using much more available .458 ammunition in an emergency.

I never understood why Winchester went to such a fast twist in the first place, since a 20" twist was perfectly adequate to stabilize a 500 grain bullet in a .45-70.

You might want to check the twist of your BRNO barrel before making up your mind on rechambering.

I juat measured the twist on my BRNO 602 .458 WM, and it's 14", so if you decide to rechamber, you can test out John Buhmiller's proposition that .458 WM loads do not shoot well with the quick twist, when fired in a lengthened chamber, like a Watts or a Lott.

Incidentally, the only difference between a .450 Watts and a .458 Lott is the length of the case, which with the Watts is 2.85" and with the Lott is 2.80". Both were formed originally from full length .375 H&H Magnum brass, and both use .458" diameter bullets.

I have rechambered two 458 Winchesters to 458 Lott. Every thing worked fine with the chamber. You know the Lott is a longer case so the Mag. has to be able to handle it. Also may be some feeding problems. One was a Pre 64 Model 70 & the other a post 64. If I remember right the pre needed some maching on the feed rails. I borrowed a reamer that was made just for this.

Looks like the Lott it is, it just seems to make sense. Even though I will be loading it to 2150 fps with 500gr projectiles,it can be done easily with less pressure and it takes advantage of the magnum sized action, as I said earlier it just make sense.

Thanks again for all your input.

If you are going to reload why not consider the 458 Express. Full 3" case with less powder compression, less pressure and less slop in the magazine. Can send you an article on a Kiwi hunter with a few trips to Africa under his belt on buff and ele and who uses a Brno originally 458W which he opened to 458 Lott and now the 458 Express. He has offered to loan the Express reamer.

PM if interested.

I have a 602, originally 458 Win mag, rechambered to Lott. No problems with rings on brass or any other kind. The 602 action is unneccesarily long for the Win, accommodates/feeds the Lott or Watts better.