All loads use 8.6 grains of Power Pistol and a Remington 2 1/2 primer. Unfortunately brass was not identical, and the powder measure may have dispensed ±0.1 grains.
Results from 6-shot string measured with a Lab Radar gen 1 at Reeds Indoor Range in Santa Clara. All velocity numbers are in feet / second, all distances are in yards, all weights in grains.
Firearm: Ruger Blackhawk, 5.5″ Barrel
|Bullet||Brass||Avg Velocity||Ext Spread||Std Dev||Approx. Drag*|
|225gr DEWC from Rim Rock Bullets||*-* plated||1077||18.6||7.5||-5.64 fps/yard|
|230gr Hornady LRN #12308||*-* plated||958||35.6||14||-1.16 fps/yard|
|250gr Lyman #454190 (Montana Bullet Works)||S&B||945||17.7||7||-0.97 fps/yard|
|255gr Bear Creek LRNFP moly coated||S&B||956||33.2||13||-1.24 fps/yard|
*Approx Drag: I plotted the velocity-measurements from a single shot in Excel, discarded obvious outliers by hand, then did a linear fit to velocity = v0 – drag•distance. Real-world drag is a function of velocity^2, and my methodology wasn’t rigorous, but this was an easy way to get an comparable number.
Conclusions: I’m surprised there’s so little difference between the 230 and 255 grain bullets. It’s less than an 11% difference in weight, but it’s still a difference, and yet the velocity is nearly identical. I’m not sure if the difference in StdDev and Spread is statistically significant. I need to run this experiment again with identical brass.
The DEWC was seated much deeper, and performed better. Looks like PowerPistol likes a bit more pressure. Or at least less space.
The Lyman #454190 lives up to the high ballistic-coefficient shown in the manuals.
I should gather seating depth numbers, and guesstimate pressure in Quickload. But it looks like this is a good example of seating depth mattering much more than weight.