458 Lott/Win mag

[M70375!]

I am looking at buying a CZ 458 lott, but will probably only shoot 458 Win mag in it, as I can seat the bullets much longer and get Lott velocity from the Win mag cases. My question is will my accuracy be less from the Lott chamber with win mag brass than it would be if I simply had a rifle chambered in 458 win mag.

 

[86thecat]

Just get Lott brass and dies.
If interested in accuracy, what's the point of jumping a bullet over .300" to the rifling? Also the CZ Safari Mag has a very long magazine and the short WM cases may cause feed issues. A 458 WM in a WM chamber will have to negotiate the funnel throat starting .010 over bullet diameter and that sometimes causes accuracy problems, especially with lighter bullets or cast. Don't drink the WM koolaid and use the Lott as designed.

 

[Brandon.Gleason]

Seems overly complicated to me. What's the perceived drawback in using Lott brass in a Lott chamber? I've had excellent accuracy from mine, and my only velocity problems have been powder limited (RL-15, specifically).

 

[hoytcanon]

You are confused about what you are trying to achieve. What is the difference between using shorter WM brass and seating the bullet long, or using longer Lott brass and seating the bullet deep?

Just use the Lott brass, and tailor the powder load to the velocity you want. H4895 is good for this.

"OR"... just buy a Win Mag rifle.

I would guess you have been reading AH threads by those .458WM guys who are constantly trying to power up to Lott levels... be careful, that is apparently a contagious virus that infects the mind and creates delusion.

 

[krish]

In a CZ 550 MAGNUM ACTION the 458 win mag cartridge could be seated a little bit longer. So what is the issue. Why go to 458 lott. I am trying to understand. The 458 win mag got a longer throat to accomplish thst. Just asking.
Krish

 

[Nhoro]

A lot(t) of people go out of their way to be unpleasant. I would like to give you a few facts and you can make your own decision.
1. Win mag chamber has a longer throat- even longer than the lott chambering. SAAMI specs.
2. Cz 550 is more suited to the lott- magazine etc is long and feeding is better suited to a lott. Shorter actions are more suited to the win mag.
3. Best of all worlds is a win mag reamed to lott. The throat is longer and you can load bullets even further out if you wish.

I have a CZ 550 that started as win mag and I reamed to lott. Lott allows a wider range of powders/ bullets etc. Win mag is capable and shorter actions are actually more suited to win mag dimensions. I found I was under pressure in Zim to find a load that was consistently available because powder and bullets are pretty variable here.I have used win mag ammo with no problems in my lott chamber. So my advice- lott in a long action and win mag in a shorter action. Best chamber is a win mag reamed to lott. Both win mag and lott are capable of any animal that walks the earth and neither needs any more power.PM me if you would like some more details on loads that I used etc.

 

[hoytcanon]

Just as easy is throating an existing Lott for longer OAL.

Buy your Lott and shoot it... if you need more, throat it.

 

[Capt_Oscar]

I have a custom Browning A-Bolt in 458Lott. I had a surplus of 458Win Mag brass and have done exactly what you are asking. This has worked extremely well with North Fork SS Bullets as the bullet itself is a little longer by its design of a solid copper shank. I have shot a bunch of 450gr in the 458Win Mag using H322 because seating the bullet out to where the bullet grooves start I get a perfect load density, no compression. Recoil is quite easy for bench range sessions. Accuracy has been wonderful. A few large (ragged) 1 hole groups at 50-75yds. Easily sub-moa at 100yds. As others have pointed out, using Lott brass and seating the bullets deep, using the same load data from the 458WM experiments yield similar results. When you push the Lott to its design specs, the recoil gets intense and bench range sessions get much shorter...

 

[baxterb]

I prefer in all cases to load to standard OAL. I have not ever felt the need to mess with loading long, etc,. I know a lot do - so be it. In a CZ with the long mag box that is already a 458 Lott I just cant see the purpose of loading a WM long. Roll a Lott, load it to 2150 (which is all Jack Lott ever wanted) and go hunting. The animals will never know the difference.

 

[Forrest Halley]

When you push the Lott to its design specs, the recoil gets intense and bench range sessions get much shorter...

Hehe yes, yes it does, but it's fun and exciting. We can't always be bored by tame cartridges such as the two-forty-three...

 

[Chuck Kazen]

A 458 win mag is of course all you'll ever "need", as it's external ballistics (500 grains at 2150ft/s) match the proven big game 450 and 470 nitro express cartridges. However, all else being equal, buy the Lott as it can fire both cartridges. Also, because of the long throat in the SAAMI spec win mag chamber the bullet actually engages the rifling sooner in the Lott. Even a win mag fired in a Lott chamber has a shorter jump to the rifling than in a win mag chamber. Not a big issue unless you want to shoot hard cast lead which should prove to be more accurate when the driving band is just off the rifling - according to the old buffalo - sorry I mean bison hunters. Look, I love the win mag, I shoot them all the time in my 458 Lott.
If you hand load, either cartridge is a joy to own.

 

[kfreeze]

I have a custom Browning A-Bolt in 458Lott. I had a surplus of 458Win Mag brass and have done exactly what you are asking. This has worked extremely well with North Fork SS Bullets as the bullet itself is a little longer by its design of a solid copper shank. I have shot a bunch of 450gr in the 458Win Mag using H322 because seating the bullet out to where the bullet grooves start I get a perfect load density, no compression. Recoil is quite easy for bench range sessions. Accuracy has been wonderful. A few large (ragged) 1 hole groups at 50-75yds. Easily sub-moa at 100yds. As others have pointed out, using Lott brass and seating the bullets deep, using the same load data from the 458WM experiments yield similar results. When you push the Lott to its design specs, the recoil gets intense and bench range sessions get much shorter...

Can I ask who did the work on the browning for you? I want to do an abolt in 458 lott.

 

[Capt_Oscar]

Can I ask who did the work on the browning for you? I want to do an abolt in 458 lott.

Bullberry Barrel Works, unfortunately Fred has since retired and his head assistant that took over the business has moved on to another shop.

 

[CBH Australia]

I had a CZ550 in .458wm from new
I did not give it a lot of use but I did feel the chambering of a round was a bit rough at times.
Not sure I would have considered it reliable under pressure.

I expect running .458wm in a Lott may be similar due to the action length.

My .375H&H loads much more smoothly.

Can you do reduced loads in Lott cases?

I have a lead on a CZ550 Lott in Australia so your timing is perfect as I probably pondered the same things myself.

Not sure I need it but , well they stopped making them so maybe I should secure one for future use

 

[Chuck Kazen]

Obviously the Lott chamber will take either win mag or Lott cartridges. There is a miss conception that win mag ammo has a longer jump to the rifling in a Lott chamber than a win mag chamber.
If SAAMI specs are followed the lands in the win mag chamber start at 3.6 inches, and the lands in the Lott chamber start at 3.1 inches. So if the concern is the long travel before the rifling is engaged, the Lott chambering will provide less jump. I believe this is a bigger accuracy issue with cast lead bullets than jacketed bullets.

 

[camperx]

I had a 458 Lott years ago on a 700 action and the mag box had to have the top part flattened to feed but nothing else needed to be done and it worked great,400 grain Barnes spitzer boat tails at 2600 fps if I remember correctly and 1 1/2 groups at 100 yards.even with a brake on it recoil was brutal off a bench but I loved that round

 

[Riflecrank]

Shooting SAAMI .458 WIN MAG ammo in a SAAMI .458 Lott is OK in a pinch,
but it will cause loss of velocity, poorer accuracy, and erode that last 0.3" of the Lott chamber
if done on a regular basis.
That 0.3" length is much wider than the base of the leade in the WIN MAG chamber, with long-leade-only throat, zero parallel-sided free-bore.
Lotts more room for bullet wobble and gas blow-by, when using the 2.5" case in a chamber meant for the 2.8" case.

All with 24" barrels and 500-gr bullets:

SAAMI .458 WIN MAG 3.340" COL, 60,000 psi >>> 2200 -2250 fps
SAAMI .458 Lott 3.600" COL, 62,500 psi >>> 2250-2300 fps

Handloaded .458 WIN MAG, 3.600" COL, 62,500 psi >>> +2400 fps
Or do the same with a .458 Lott having had throat lengthened by running a SAAMI .458 WIN MAG reamer into it, or a SAAMI .458 WIN MAG rechambered with a SAAMI .458 Lott reamer.
Same same.
I passed on the Lottite Koolaid.