quote:

turn that wimpy 470 mbogo into a mans gun!

You might want to try actually owning a big bore (or even shooting one!), before you start talking smack like that! Wimpy!!! grrrrr...



Cheers,
Canuck

quote:

Originally posted by makeminestainless:
Should the Lott have a longer freebore? I've heard others mention that a converted Lott from a Win actually has a longer distance to the rifling than a standard Lott. If the whole mess was moved forward 1/4" instead of just the space for the brass (giving the Lott the same long throat as the Win) would this help? I ask this as a novice but feel free to rip me a new one ...

Rip ripped you an old one. Now the new one:

Studying old reamer drawings from Clymer, I stated previously that the .458 Lott had a more traditional throat with .4" of tight and parallel-sided freebore and a usual kind of leade (1.5 to 2 degrees, don't recall exactly) that petered out over an additional 0.3", for a total throat of about 0.7000" (freebore plus leade).

I stated that the .458 Win Mag had a wide and sloppy funnel-of-a-throat (FOAT) that was only a gradual leade angle that petered out over a total run of about 1.1".

Now I have studied both throats in the latest CIP specs of May 15, 2002:

Lo and behold! The .458 Winchester Magnum (2.500" brass) and the .458 Lott (2.800" brass) both have the same FOAT now, standardized by CIP. Hopefully SAAMI is the same.

Starting at each of the case mouths:
chamber neck diameter at case mouth = .4831"
then
abrupt 45-degree step down to throat
then
diameter at start of throat = .4690"
then
leade angle = 0-degrees, 29-minutes, 30-seconds
resulting in
total run until the leade tapers down to land diameter = 1.1083"

There. I ripped you and me both a new one.

Pressure (Maximum Average) is same for both cartridges too:
4300 bar = 62,350 psi

quote:

Originally posted by Canuck:

quote:

turn that wimpy 470 mbogo into a mans gun!

You might want to try actually owning a big bore (or even shooting one!), before you start talking smack like that! Wimpy!!! grrrrr...



Cheers,
Canuck

glad you have a sense of humor...

quote:

Originally posted by jeffeosso:
the lott would have been perfect if factory loaded at 2200, with lower pressure than the 458lott.

Will, man, your reads that "you don't care about pressure"

of course, if you make a winnie go 2200 with 500gr bullets, you are WAY over pressure, with powders available to reloaders.. let's not mention the "freak" heavy mag loading from hornady... it can NOT be duplicated by a reloader and be under spec pressure

This post is untrue. Try reading the Hornaday manual, most recent eddition. 2250 is possible in some rifles with under max pressure. The max loading of AA2230 is shown at 2250. From a Ruger, iirc, with a 24" barrel.

The same loading is shown in manuals that pre-date the brass? solids too.

Hell, I get 2135 from a near starting load of AA 2230 with 500 grainers and out of a double rifle. I've had my ammo pressure tested and it WELL below max pressure. I would load hotter, but this is the load that matches barrel regulation in my rifle. Plenty for elephants, btw.

JPK

I don't know squat about the big bores. It's all new to me. But from what I've read in the past, the 458 WM is more than adequate for anything that still walks this earth. The early on complaints that I read about with 458 WM failures was due to poor bullet selection. To my way of thinking, if I can get 458 WM velocity with from a Lott with reduced pressure and more dependability in the hot weather I would be more than tickled. I know that I have to do my part no matter what smoke pole I'm carrying or monster bullet I'm shooting. Loading reasonable and dependable, doing my part in hitting the beast right will sure help to keep me from becoming part of the terra ferma. Me thinks that safety and dependability mean more than a high performance race bullet - cartridge combo. Now you guys can kick my novice butt.

I just picked up my first 458 WM Douglas barrel tonight and am on my way to cooking up a big bore. My thoughts were to open her up to a lott and keep pressures down and velocityies reasonable. I already have quit a few hot rod guns that go fast. They are not for beasts that get pissed and get even. I guess I'll learn as I go and by reading the big bore forum.

Lott got "scared" by a buff and was reportedly the reason for goosing up the performance of the 458 WM. And if you were a well-known gun writer you too would have a chance of naming a cartridge after yourself. If Boddington wasn't so many letters we may have had the 375 Boddington instead of the 375 Ruger!

Anytime you get scared the natural tendency is to go bigger ("no such thing as too much gun," to quote somebody I know!).

I still do not see the point of building a Lott unless you are running at max loads. Otherwise use a 458 WM, at max loads. But if you want to run squid loads in a Lott, go ahead. But you can get a Lott to 2300 fps, which was the original question.

And with all the great bullets now, the Lott at 2200 fps or even 2100 fps probably performs better than anything available in the "old days."

quote:

Originally posted by Will:
I still do not see the point of building a Lott unless you are running at max loads. Otherwise use a 458 WM, at max loads. But if you want to run squid loads in a Lott, go ahead. But you can get a Lott to 2300 fps, which was the original question.

I think you meant squib loads, as *I* haven't ever heard of squid hunting with a lott. Is that dangerous game, or more like skeet?

if the lott was loaded to 2200fps, the pressure would be far lower than trying to jack up a 458 winmag to 2150, much less trying to get that next 50 FPS

but reloaders would know that the last 50FPS in a high pressure load is VERY expensive in terms of pressure and destroying brass. nonreloaders sit back and speculate

Hey There I have the CZ 550 Safari Mag. in 458 Lott and I get over 2300 FPS with my rifle shooting a 500gr bullet. Not everybody own and shoots the same rifle.

I got 2300+ fps but it was not my intention to do so. I started at what I thought was a safe load, but was over the 2300 fps MV right off the bat. Too fast, not necessary etc... like I think the fastest over the Chrony was about 2350 fps...

I immmediately went back to the bench, reduced the powder until I found the ideal 2250 fps MV.

I don't have the loads data at hand, so I cannot quote any numbers. The rifle is a CZ-550 with standard 23.5" barrel.

quote:

Originally posted by Showbart:
Yes Mac, that's the point! Not more than 2150. Just 2150! Maybe a wee bit more, whatever some of these accurate loads work out to. But to lessen pressure too is a goal.

My point exactly, the LOTT is what the 458 Win Mag should have been in the first place, but it doen't need to run 2300 fps! What advantage it has over the 458 WM, IMO, is that gives one more room for the powder, to do the velocity that the 458 WM advertized, with lower pressures. The extra speed wasn't needed, just a little more powder room for the easy 2150 fps, with a 500 gr bullet. When compared to the 450NE's 2150 fps with a 480 gr bullet,which did a great job, it is still a better penetrator, at the same speed of 2150 fps with the extra 20 grs of bullet weight, and the lower chamber pressure,than the 458 Win Mag, to do the same job. In addtion, you can use the 458 win mag in the lott chamber, in a pinch. That is evident on the loading table, before you even get into the field.

Although, Will has generously offered to pay for 60 cape Buffalo so I can prove it one way or another!

Thanks RIP! That should really confuse the issue as everybodys Lott will be all kinds of different.

Jeffeosso, are you saying that the data for 2190 FPS at 53K using AA2460 is unlikely to be true? Or do you think 53K is high pressure? What pressure do you think one should try for to be Africa ready?

Demonical, your 550 has a 23.5-inch barrel? The CZ Lott that I had had a 25-incher -- standard........ What gives?

Measuring from the front of the front ring.

Barrel length includes the chamber. Stock CZ 25".

Maybe he means a standard .458 caliber factory barrel from CZ that was shortened from 25" to 23.5"?
And that would be a 1:14" twist, right?
Hammer-forged.

Will, If I recall correctly, Lott got a mudhole stomped in his ass by a buff that he could not stop at close range with the Win. I believe that he was laid up for quite a while. That is just a bit more than "scared" in my book!!! Lee.

Only because he blew the first shot and hit the critter in the guts. A 577 would have done no better. But by Will's reasoning, he shoulda been just a bit put off.

JPK

I tend to agree with MacD37. the 458 lott was a way of driving a 500gr bullet to 2150fps with out the problems of higher pressure and severely compressed loadings of the 458 win mag.
No I haven't taken 40-60 or more buffalo but have taken a 2 or 3 really mean looking prairie dogs in rut and some charging milk jugs.
Bill

quote:

Originally posted by makeminestainless:
Thanks RIP! That should really confuse the issue as everybodys Lott will be all kinds of different.

Jeffeosso, are you saying that the data for 2190 FPS at 53K using AA2460 is unlikely to be true? Or do you think 53K is high pressure? What pressure do you think one should try for to be Africa ready?

I haven't seen the data, yet I strong suspect the units for that 53K are CUP not PSI ... and 53k CUP is seriously crowding max pressure as read in PSI. while not a direct figure, add 8 to 9 K to convert cup to PSI

and, if the winmag can do it at 53K ANYTHING the lott would do so at much lower pressure, using the same techniques to load

PSI is what is in the Accurate website data. I assume it is correct but who knows for sure.

quote:

Originally posted by JPK:
Only because he blew the first shot and hit the critter in the guts. A 577 would have done no better. But by Will's reasoning, he shoulda been just a bit put off.

JPK

How in the world can you even think about contributing to this discussion. Everyone knows you are so over-pressure shooting 458's in your double that the rifle shouldn't last through a box of shells!

quote:

Originally posted by Whitworth:
Demonical, your 550 has a 23.5-inch barrel? The CZ Lott that I had had a 25-incher -- standard........ What gives?

The barrel has not been cut down. I guess I am not measuring the barrel correctly (leaving out the 1.5" that threads into the receiver?).

Phil,
"officially" according to the ATF, you should drop a rod into the barrel, with it resting on the boltface, and measure to the muzzle.

generally, .68 to 1.0 inches past the receiver ring

[QUOTE]Originally posted by Demonical:
I got 2300+ fps but it was not my intention to do so. I started at what I thought was a safe load, but was over the 2300 fps MV right off the bat. Too fast, not necessary etc... like I think the fastest over the Chrony was about 2350 fps...

I immmediately went back to the bench, reduced the powder until I found the ideal 2250 fps MV.

I don't have the loads data at hand, so I cannot quote any numbers. The rifle is a CZ-550 with standard 23.5" barrel.[/QUOTED


With my CZ 550 Safari Mag. Top fps was 2355 FPS
My rifle has a 24" barrel so I droped down 1 Gr
And now I get 2320 with those solids. With the
Soft nose I get 2280 I could go to 2300 but 2280 is good enought without any signs of overload with powder. I use IMR4320.

quote:

Originally posted by jeffeosso:
Phil,
"officially" according to the ATF, you should drop a rod into the barrel, with it resting on the boltface, and measure to the muzzle.

generally, .68 to 1.0 inches past the receiver ring

Jeffeoso,
At .68 to 1.0 past the receiver ring, are you checking with the bolt open? The bolt locks up in the receiver ring doesn't it? A rod dropped down the muzzle bottoming out on the bolt face in battery position would be the correct length of barrel. You lost me with the .68 to 1.0 past the receiver ring. Am I missing something there?

CZ's have an extra 1" of bbl.

FYI, the A-Square reloading manual, which is the bible of pressure tested data as far as I'm concerned, lists the maximum pressure for the Lott at 62,400 piezo psi or 53,700 CUP, just like many other modern high powered rifle rounds.

BTW, A2 lists many safe loads just under and over 2,400 fps using its 465 grain bullet out of a 26 inch barrel.

I think a 450 grain bullet at 2,450 or so would be even better than a 500 at 2,300 and that is where I am headed.

quote:

Originally posted by olcrip:

quote:

Originally posted by jeffeosso:
Phil,
"officially" according to the ATF, you should drop a rod into the barrel, with it resting on the boltface, and measure to the muzzle.

generally, .68 to 1.0 inches past the receiver ring

Jeffeoso,
At .68 to 1.0 past the receiver ring, are you checking with the bolt open? The bolt locks up in the receiver ring doesn't it? A rod dropped down the muzzle bottoming out on the bolt face in battery position would be the correct length of barrel. You lost me with the .68 to 1.0 past the receiver ring. Am I missing something there?

He means passed the front of the reciever, with the bolt closed!