18 February 2004, 03:51
ScottSRe: From the Archives 500 A^2 Load Development - MAX
Dave,
The brass was necked up Weatherby, 460 Weatherby magnum brass. It was recycled from my 460 Weatherby magnum. I built the 500 after I had sold the 460 WM MkV. I have always assumed this stuff was Norma brass.
The brass was a little short. It's overall length was around 2.85".
Scott
17 February 2004, 05:48
ScottSThough some may find this interesting. The data was compiled from a rebarreled Ruger No1. The barrel length was 27" with an additional 1.5" of muzzle brake.
Brass had a volume of ~ 142 gr of water.
Bullets were Barnes 600 gr monolithic solids
Primers - Fed 215
Data is several years old, but I will try and answer any questions. This data represents the maximum load this particular rifle would shoot without sticky extraction and/or blown primers.
Corrected chronograph velocities (chrony was 12' from muzzle)
2311
2266
2298
2258
2284
2271
2305
2296
2280
2288
Average velocity of 10 shot string - 2286 fps
Extreme spread of 10 shot string - 53 fps
Standard Deviation of 10 shop string - 17.3 fps
Group size (5 shots only) 3".
This was NOT the most accurate load, but it was the MAXIMUM load in this rifle. The best load was a consistent 2" grouper, but only had an average muzzle velocity of 2087 fps with this bullet.
Scott
17 February 2004, 15:09
470 MbogoHi Scott,
That data is old enough and low enough to show signs of A-Square brass. Any other brass and a 27 inch barrel would show velocities well over 2400 fps. Is that the case. Pun intended.
Dave