Not much activity in here. Got a chance to shoot some of my latest 10mm loads out of a stock G20 today and thought I'd post something:
VV N340, loaded to 1.260 OAL, Bullets are all Montana Gold. Brass is new Starline brass. Lit with Winchester Large/Magnum Primers. Temp was around 82 deg.
10 rounds each.
9.0grs under 155 JHP -> 1317 fps, SD 10fps
8.6grs under 165 JHP -> 1239 fps, SD 8 fps
7.8grs under 180 FMJ -> 1139 fps, SD 4 fps
7.0grs under 200 TMJ -> 1039 fps, SD 4 fps
These loads range from 41,400 psi to just under 44,000 psi according to Quickloads's calculations with corrected case capacity using (H20). My goal was to stay under the original 10mm 44,000 psi spec pressure.
I didn't see any signs of overpressure but will clean up the brass and re-inspect. I'm sure there's room to go up but it'd probably be easier to start with a more appropriate powder.
Accuracy was good. Shot at 25 yards off a bench and the smallest 10 shot group was only about 3.5" with the largest group being approx 6.5".
For reference I also shot two factory loads I found at Cabelas:
Buffalo Bore 180gr Gold Dots -> 1284fps w/ SD of 18.
Hornady 200gr XTP -> 1030fps w/ SD of 38.
Have fun and please work your loads up carefully.
Last edited by Lithium; 07-11-2007 at 05:02..