450 gr A-Frame

[Davidm]

I'm planing to load the 450 gr A-Frame for my Brno zkk 602 in 458 lott. I've only access to norma powders, mainly norma 201 and 202. I have looked at the max loads for the same bullet in the 458 wm and thinking about using them as starting loads. The max is 75gr of each powder. Have any of you tried this bullet with norma powder? And what kind of velocity can I expect? 2300-2400fps?

 

[Bullthrower338]

Funny the Norma manual doesn’t list the 450gr A-Frame for the Lott but it does for the WM!
I would start around the upper end of WM data and work up from there.

 

[Dr Lott]

When the reloading data looks like this for the 458 win mag (from an old Norma manual), is it better to take the slower 202 vs 201 for the Lott, or vice versa?

 

[fourfive8]

I agree with the logic of starting upper end (maybe 75% of listed max for the WM) and work up. That’s exactly what I do with my Lott cousin. I’ve had no issues. Use a chronograph, record standard deviation of velocity numbers as you work up load, set realistic velocity objectives, pay attention to signs of excessive pressure, record accuracy data. Do what you want for an objective velocity, but I found about 2250-2300 fps with a 450 gr bullet is a nice place to be.

Just looking at the Norma data posted, both powders look fine. It’s one of the beauties of the straight wall case- the built-in higher expansion ratio of the design tends to make for more consistent and predictable internal ballistics.

 

[crs]

Dr Lott, thank you for posting the .458 Win Mag page from the Norma manual. The data confirms my findings that my .458 2.4 loads are well up into the .458 Win mag range. Powder is VV N133.

From their field performance on Ele , Cape Buff and Bison I already knew that they were lethal.
In the rifle below and my .458 2.4 DR the velocities are :
North Fork 350 SS Vel = 2300 fps.
North Fork 450 FPS Vel= 2150 fps.
Old fashioned numbers from an old fashioned rifle - Miroku/Winchester 1886: