458 Lott loads IMR4320?????
I have been using IMR 4320 in my Lott with Hornady 500g softs and have gone as high as 80 grains. I was wondering where other posters have gotten thier accuracy at? I am conflicted about loading heavier even though I have seen no pressure signs.
My loading manuals show the following:
Hornady #7 64.2 min and 73.6 at max 2250 fps.
Barnes #3 76.0 min and 81.0 at max 2323 fps.
And then Steve's pages show 64.2 min to 85.0 max.
This seems like a large range to me. Iwas just curious what others have loaded this powder to.
And yes I do understand that all rifles are different and any load given should be worked up to.
Just curious, and thanks.
13 May 2008, 06:30
Hog Killer500gr, 84.0gr 4320, 2280fps
Keith
Hey Keith, glad to see you posting. I had been wondering where you went.

I use IMR4320 85grs in my 458 Lott for all 500gr bullets.
Thanks!
I sure was curious, I will keep working up carefully. I think I had already made uo my mind to anyway.
83.0 grains of IMR-4320 with Fed-215 using Barnes 450 TSX and Banded Solids at 2420 fps. They did everything I wanted.
Bull1
14 May 2008, 19:49
AtkinsonThat is the only powder that I could get 2350 FPS with a 500 gr. bullet and still be in the safe zone.
As far as I'm concerned its the only powder for the Lott...My load was 83 grs. of IMR-4320 for just a bit over 2300 FPS. It gave me .0003 head expansion, superb accuracy, and more than enough velocity in the 26" tube. I loaded up to a good bit beyond the max of 85 grs. in my testing and got a little over 2500 FPS and pressures were very high with extractor marks and flat primers and case head expansion was right up there, I reloaded one of these cases 4 times and it was showing signs of fatigue, but I knew where the max was for sure with that rifle.
Recoil is right up there with my 83 gr. load and got horrendous as I went up..
Most Lotts work well with 82 grs. of IMR-4320 and a 500 gr. bullet..Its a sure killer.
BTW I always turn the expander ball down .003 or .004 on my Lott dies and use a powder that pretty well fills the case and a good crimp and never have had a bullet set back.
Rifle magazine no. 135, May-June 1991 has a great article on loading the 458 Lott by G. Sitton.