Big ol' enaa baasee' to Sir MedRiver and Sir Con for the latest contributions to the Square Table.
Sir Names are now assigned by the Hand of the King unless said Sir wants to change it.

Originally Posted by MedRiver
I apologize as I have not kept up on all 156 pages of this treasure trove! I have, however, just started playing with a new-to-me .458 WM. This is Colombian M98 that someone did a nice job of converting to .458 Win mag. It had a cheap plastic stock so I restocked it with a used McMillan that is pillar and glass bedded. With some very minor alteration to the feed ramp it now feeds everything up to 500 grain RN very well. It has a 26" barrel that will likely be cut back a fair bit and a ruger banded front sight installed. The scope is just for some initial testing and I am thinking different bases for QD rings and a 1.5-5x20....or maybe just irons.

[Linked Image from i.imgur.com]
[Linked Image from i.imgur.com]

Anyway, I loaded up some rounds with Accurate 2230 using Hornady data and their 500 RN FMJ. The book shows a max load of 78.3 grains at around 2200 FPS from a 24" barrel for the DGS and DGX bullets. I broke 2300 FPS with just 76 grains and a 26" barrel in 40 degree weather with the FMJs. With the .458 bore I wouldn't expect much gain/loss between a 24" and 26" barrel so was pretty surprised at how hot these loads were, especially given the cool temps I was shooting in. Even though bolt lift and extraction were fine, I am going to back off some.

Has anyone found extreme lot to lot variation with the Accurate powders?


Sir MedRiver,
I would not be surprised if you had a variant, short chamber, maybe even as short as a .458 Lott.
You need to put an inverted, flat-based bullet with a long shank in a 2.500" case and see how long you can stick it.
SAAMI slug jump is 0.6725" from a 2.500" case mouth with a 0.458" diameter of right cylinder slug.
Also slug for groove diameter and check twist of the barrel.
If all is SAAMI, you have a great barrel.
Going from 24" to 26" will gain you only about 10 fps per inch, and lesser gains past 26".
20" to 24" is about 15 fps per inch of barrel length.
Shortening below 20": 20 fps per inch and greater loss rate the shorter you go.

I have not seen or heard of much lot-to-lot variation in AA-2230 of 2016 or later vintage when it
and brother AA-2460 were reformulated for better ThermoBallisticIndependence (TBI).

In SAAMI chambered .458 WinMag, verified by me,

500-gr TSX at 3.78" COL (longest possible) in a 24-7/8" CZ barrel for .458 WinMag: 2342 fps corrected to MV: 83.0 gr AA-2230, Hornady brass/F215

500-gr Trophy Bonded Sledghammer Solid at 3.550" COL in a 24" Ruger No. 1 .458 WinMag: 2408 fps LabRadar MV: 83.0 gr AA-2460, W-W brass/F215

The TBSS was at 80*F, and same session the Hornady Factory 500-gr DGS load gave exactly 2140 fps MV by LabRadar, from same 24" Ruger No. 1.

I do not doubt your results a bit.
If you use Norma brass you will be able to shorten the long COL loads by 0.100" of COL and have same net case capacity
as the longer COL loads with W-W, Hornady, or R-P brass.
Just a reminder.

Ron aka "Rip" for Riflecrank Internationale Permanente
NRA Life Benefactor and Beneficiary
.458 Winchester Magnum, Magnanimous in Victory
THE WALKING DEAD does so remind me of Democrap voters. Donkeypox.