I was a bit surprised to see Longshot as one of the higher velocity on Hogden reloading data. I thought that the powder would tend to be a bit slow to use in a shorter barrel pistol. Since I recently acquired a CZ Scorpion with a 7.75" Barrel, I thought it might take advantage of slower burning powder.
Results from a LabRadar unit.
CZ Scorpion w/7.75" Barrel - 6.0g Longshot pushing 115g Xtreme plated Hollow Point.
10 Shots
Average: 1350
High: 1372
Low: 1319
Extreme Spread: 53
Std Deviation: 16.2
I also ran a clip full through a short Barrel.
CZ 2075 RAMI w/ 3" Barrel
7 shots
Average: 1103
High: 1116
Low: 1091
Extreme Spread: 25
Std Deviation: 9.8
Plenty of flash from the short barrel.
I didn't see any signs of high pressure and may push a bit more to see where it ends up. Plenty of room in the case.
Greg
Yes I saw the Hodgdon book load showing 6.0 grains of LS under the 115 gr, your results are very close to the book data which is based on the 4" barrel. Thanks for the report. :D
More data for the Scorpion 7.75" barrel.
These loads are over Hogden (except the 6.0g), so be careful and work up. 5 shot strings.
Longshot 6.0g
Stats - Average 1355.38 fps
Stats - Highest 1367.84 fps
Stats - Lowest 1346.27 fps
Stats - Spread 21.57 fps
Stats - Std. Dev 11.02 fps
Longshot 6.1g
Stats - Average 1372.11 fps
Stats - Highest 1401.48 fps
Stats - Lowest 1354.07 fps
Stats - Spread 47.41 fps
Stats - Std. Dev 17.64 fps
Longshot 6.2g
Stats - Average 1388.76 fps
Stats - Highest 1406.14 fps
Stats - Lowest 1372.77 fps
Stats - Spread 33.37 fps
Stats - Std. Dev 14.36 fps
Longshot 6.3g
Stats - Average 1384.3 fps
Stats - Highest 1398.4 fps
Stats - Lowest 1371.01 fps
Stats - Spread 27.39 fps
Stats - Std. Dev 11.16 fps
The CZ Scorpion showed no ill effects from these loads. I might try 6.4g because the loads were getting smaller deviations as the loads increased from 6.1 grains. The last load was shooting about as good as my old eyes with iron sights can manage.
Greg
I was wanting to understand the decrease in velocity with an increase in powder charge a little better, so I ran some new loads and shot 10 shots in the individual series. There is a plateau!
6.0 Longshot
Shot ID V0
1 1297
2 1347
3 1367
4 1348
5 1345
6 1342
7 1335
8 1361
9 1372
10 1348
Stats - Average 1346.24 fps
Stats - Highest 1372.09 fps
Stats - Lowest 1297.15 fps
Stats - Spread 74.94 fps
Stats - Std. Dev 20.74 fps
Longshot 6.1g
Shot ID V0
1 1356
2 1367
3 1401
4 1350
5 1380
6 1374
7 1345
8 1381
9 1363
10 1353
Stats - Average 1366.9 fps
Stats - Highest 1400.71 fps
Stats - Lowest 1345 fps
Stats - Spread 55.71 fps
Stats - Std. Dev 17.19 fps
Longshot 6.2g
Shot ID V0
1 1366
2 1421
3 1400
4 1376
5 1372
6 1370
7 1370
8 1357
9 1368
10 1345
Stats - Average 1374.58 fps
Stats - Highest 1421.26 fps
Stats - Lowest 1345.12 fps
Stats - Ext. Spread 76.15 fps
Stats - Std. Dev 21.57 fps
Longshot 6.3g (last shot wasn't recorded because I wanted to see if Labradar would record a double tap. It didn't ;D
Shot ID V0
1 1361
2 1384
3 1416
4 1389
5 1386
6 1394
7 1366
8 1365
9 1358
Stats - Average 1380.16 fps
Stats - Highest 1416.14 fps
Stats - Lowest 1358.47 fps
Stats - Spread 57.68 fps
Stats - Std. Dev 18.95 fps
Longshot 6.4g
Shot ID V0
1 1356
2 1385
3 1407
4 1400
5 1378
6 1385
7 1373
8 1373
9 1357
10 1388
Stats - Average 1380.2 fps
Stats - Highest 1406.68 fps
Stats - Lowest 1356.25 fps
Stats - Spread 50.43 fps
Stats - Std. Dev 16.29 fps
The plateau went up a tenth of a grain, but still only 6 fps total over .2g charge increase. I guess I'm a gun powder geek :o
Greg
Greg these were also shot from the CZ Scorpion with a 7.75" Barrel?
Yes.