I pulled out a Winchester M70 .458 Win. Mag. I have not shot in 10 years.
It is a mid 90's model after Winchester decided to go back to CRF with the old
Monte Carlo stock design and 22" barrel.
Last week I found 5 one pound AA2230's at Gander Mt. and decided to do a little load
development with some H335 I had.
I had 50 new cases of Hornady brass and 100 rounds of Hornady 500 Gr. DGS solids.
My goal was a reasonable load that would give me 2125-2150 FPS average. The results
turned out to be very satisfactory.

Chronograph 12 ft from muzzle, Temp. 74 Degs., All 5 shot strings.

Bullet- Horn. 500 gr. DGS
Powder- AA2230
Primer- Fed. 215GM
Case- Hornady

Charge- 74.0 Grs.
FPS- 2190,2178,2178,2185,2182. ES- 12, SD- 5, Avg.- 2183

Charge- 73.5 Grs.
FPS- 2171,2178,2185,2175,2171. ES- 14, SD- 5, Avg.- 2176

Charge- 72.5 Grs.
FPS- 2150,2159,2143,2147,2157. ES- 16, SD- 6, Avg.- 2150 (Load I chose for this rifle)

Charge- 72.0 Grs.
FPS- 2147,2136,2140,2129,2143. ES- 18, SD- 6, Avg.- 2139

H335. All other components the same except powder. Load used is maximum Hornady manual listing.

Charge- 76.3 Grs.
FPS- 2147,2160,2154,2154,2150. ES- 13, SD- 4, Avg.- 2153

For AA2230, no noticeable compression until 73.5 grs., H335 showed some compression at 76.3 grs.

Thanks, very good info for those that enjoy the great .458 Winchester magnum round. I've been shooting a couple of .458's for years now and after all the powder trials, have been currently using 335 Hodgdon. Have alway heard great things about the accurate 2230 so will have to give it a whirl.
Thanks again for the informative tests that you did.
Kidd