Gents,

Does anyone know what the pressure might be if the 458 Lott is loaded to 2150 with a 500 grainer?

Roger QSL

I think you will find pressure also depends on the powder used.

416,

Let's try it this way.

This was an actual chrono load....
79 grains 4320 2151fps

Does this help?

Roger QSL

With the IMR-4320 load at 2100 in the above post, the pressure is super mild..That powder can safly get you 2350 FPS at 84 grs. so lets figure the figure that Rogers load is 5 grs. under max...that would be close.

QSL,



For you load, 79 grains of IMR4320 and your 500 grain pill, I am calculating a pressure of ~ 54,500 psi +/-.



I assumed a barrel length of 24" and a 500 grain Hornady. That will effect the pressure calculation is the barrel length is different.



Regardless, you should be well below the SAAMI maximum allowable of ~ 62,000 psi.



Ray seems to be right on this one, it does appear to be a "mild" load (I would not go so far as super mild though, but that is just me I guess)



ASS_CLOWN

Gents,

As my shooting library is currently packed away in moving boxes, (semi-retirement in Arizona) do any of you have a load that gives 2150 with a 500 grain, using 3031.
Would like to stay with a low presure load if possible.
If this load creates a low powder capacity situation, I'll pass on it. Not wanting to create mis/fires or worse hangfires.
Ray and ASS CLOWN, thanks for your help. Great to see the participation of such varied views.

Roger QSL

ASS CLOWN,
Somewhere in your pressure figuring there is a difference of opinnion with mine, and it pops up now and then...

This 79 gr. or IMR-4320 load could not possibly be above 50,000 PSI and more likly below 49,000 PSI....I had the pressure data at one time from Whites Lab. and it was in the high 40's somewhere, I don't recall the exact numbers....

Now I will stipulate that all of my guns had .600 inch free bore as I have found that necessary with any 458 Lott to get enhanced velocity or to reach the goal of 500 grs. at 2350 FPS with 84 grs. of IMR-4320, a max load in most of the 458 Lotts that I have played with except two that would handle even more, but then recoil became a deciding factor, at least with me......

I would assume that any good smith would know the advantage or .600 in the 458 Lott and use that criteria in chambering.

For more information on the 458 Lott and its history and loading, I suggest one Read "THE 458 LOTT" by G. Sitton, Rifle No. 136, May-June 1991....Very informative. I read it in 1991 and that was my introduction to the Lott and the reason I built my first rifle, and 2nd and 3rd and even a 4th..sold them all eventually....

Lots of recoil was my only complaint with them...and in certain field positions they hammered me a couple of times a little too much...I settled on the 416 and 404 for that reason..a personal choice.

Ray,

With the amount of experience you have had with the Lott, how would you compare the Lott to a 375 in recoil. This would be with the 500 at 2150 and a 375, 300 at 2550.

Roger QSL

There is an order of magnitude difference between the lott's recoil and that of a 375. You can shoot a 375 in any position, and ignore the recoil. I couldn't say that of the 458, it really takes extra concentration before squezing the trigger. I've never flinched nor hurt myself with a lott, but it's recoil is on a different level than the 375.

Honestly I couldn't much tell the difference between a 2100 and 2280 fps load with 500's in the Lott. When you drop down to 350 gr @ 2400-2500 fps, then you're back to 375 levels and can ignore the recoil. A 500 gr at a useful hunting velocity generates noteable recoil.

QSL,

I can answer that (recoil comparison) as I spent today sighting both a 375H&H and 458Lott at the range. My 375H&H is a Rem Safari Classic (pretty light) with Decelerator pad and the 458Lott is a CZ550 with an F990 pad and an extra kilo in weight compared to the Remington. Shooting off a bench, the 375H&H is a toy in comparison, whilst 20 rounds of the 458Lott left me a little "twitchy". As a 458WM the CZ was a piece of cake to shoot, loaded up into the 2250+fps level the 458Lott takes on a life of its own and is just plain uncomfortable off a bench.

Cheers...

Con

Ray,

Please post the H.P. White lab results you have sited.

Quote:

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This 79 gr. or IMR-4320 load could not possibly be above 50,000 PSI and more likly below 49,000 PSI....I had the pressure data at one time from Whites Lab. and it was in the high 40's somewhere, I don't recall the exact numbers.

---

Your recollection of pressures seems very close to what is published in A Square's book "Any Shot You Want". Problem is A Square loaded the 458 Lott with 465 grain pills. So their pressures are going to be much lower than what would be achieved with the 500 gr pills.

You have accused me of BSing Ray, now come clean and post your actual data. I can find NO industry reference that supports your statements. They all more or less fall in line with my estimation of ~ 54000 psi. At 2250 fps the Lott is steamin along in the 60000 + psi range. To get it to 2350 requires 65000+ psi pressures. This is easily doable, but NOT recommended!

ASS_CLOWN

BTT, still waiting on those lab reports of yours Ray.

ASS_CLOWN