Today I got to go to the range with my new toy I got for Christmas, a ProChrono Digital chronograph. I also got the Bluetooth module for it, which makes it real nice to set new strings without having to go downrange and punch the buttons on the face of the chrono. I had a great time and it was so nice to work with a chrono that isn't giving constant errors like the Caldwell I was using before this one.
I brought 2 calibers to play with today; 357 Mag and 44 Mag. And I brought my 629 Classic (6 1/2" barrel) and my 627 Pro (4" barrel) for pistols and my 357 Rossi model 92SRC and my 44 Mag Browning B92 for rifles, which both have 20" barrels on them.
The loads I shot were as follows:
357 Magnum:
All loads used CCi 550 small pistol magnum primers except the PMC Bronze factory ammo I shot 1 string with.
I used 2 different Hi Tek coated MBC bullets, the 140 grain TCFP "Zinger" bullets and the 180 gain RNFP "Striker" bullets. All were crimped in the crimp groove on the bullets with a hard roll crimp.
String 1:
627 Pro
180 grain Striker
13.5 grains H110
Avg velocity - 1014 ft/sec
Max velocity - 1064 ft/sec
Min velocity - 971 ft/sec
Spread - 93 ft/sec
Standard deviation - 31
Muzzle Energy - 376-452 ft/lbs
String 2:
Rossi
180 grain Striker
13.5 grains H110
Avg velocity - 1425 ft/sec
Max velocity - 1460 ft/sec
Min velocity - 1400 ft/sec
Spread - 60 ft/sec
Standard deviation - 19
Muzzle Energy - 783-851 ft/lbs
String 3:
Rossi
180 grain Striker
11.2 grains Accurate #9
Avg velocity - 1480 ft/sec
Max velocity - 1501 ft/sec
Min velocity - 1454 ft/sec
Spread - 47 ft/sec
Standard deviation - 14
Muzzle Energy - 844-900 ft/lbs
String 4:
Rossi
180 grain Striker
13.4 grains IMR 4227
Avg velocity - 1399 ft/sec
Max velocity - 1415 ft/sec
Min velocity - 1378 ft/sec
Spread - 37 ft/sec
Standard deviation - 11
Muzzle Energy - 758-800 ft/lbs
I had some H110 Striker loads left over from last time I did some chrono work that were loaded with a different lot of powder, and this illustrates why you need to check yourself when going from one lot to another with the same powder. These were loaded with 13.0 grains of a different lot of H110 from the powder used in string 2.
String 5
Rossi
180 grain Striker
13.0 grains H110 (different lot of powder)
Avg velocity - 1463 ft/sec
Max velocity - 1503 ft/sec
Min velocity - 1416 ft/sec
Spread - 87 ft/sec
Standard deviation - 22
Muzzle Energy - 801-902 ft/lbs
I then re-ran the new lot H110 loads with the 13.5 grains of powder, just to see how close they repeated string 2.
String 6
Rossi
180 grain Striker
13.5 grains H110 (same as string 1)
Avg velocity - 1441 ft/sec
Max velocity - 1466 ft/sec
Min velocity - 1407 ft/sec
Spread - 59 ft/sec
Standard deviation - 18
Muzzle Energy - 791-858 ft/lbs
Now to the 140 grain Zinger strings
String 1
Rossi
140 grain Zinger
12.5 grains Accurate #9
Avg velocity - 1592 ft/sec
Max velocity - 1654 ft/sec
Min velocity - 1550 ft/sec
Spread - 104 ft/sec
Standard deviation - 27
Muzzle Energy - 746-850 ft/lbs
String 2
Rossi
140 grain Zinger
17.5 grains H110 (old lot)
Avg velocity - 1921 ft/sec
Max velocity - 1940 ft/sec
Min velocity - 1875 ft/sec
Spread - 65 ft/sec
Standard deviation - 18
Muzzle Energy - 1092-1169 ft/lbs
Finally, a string of some PMC Bronze I bought a few years ago when it was so hard to find brass.
Rossi
158 grain JSP
Avg velocity - 1654 ft/sec
Max velocity - 1685 ft/sec
Min velocity - 1594 ft/sec
Spread - 91 ft/sec
Standard deviation - 26
Muzzle Energy - 891-996 ft/lbs
I only ran 3 strings of 44's. I ran a string in the pistol and rifle loaded with some 165 grain JHP bullets that were a production overrun for Cor Bon that I bought from Midway around 3 years ago. I wish Sierra would produce these for reloaders as they are a blast to shoot and give lower recoil than heavier bullets. I haven't shot any kind of critter with them, but I imagine they should blow stuff up as you can get them moving. The third string I ran was out of the rifle with some coated Bayou 240 grain SWC bullets loaded to mid-power with Longshot.
String 1
629 Classic
165 grain JHP
19.0 grains Blue Dot
Avg velocity - 1627 ft/sec
Max velocity - 1664 ft/sec
Min velocity - 1596 ft/sec
Spread - 68 ft/sec
Standard deviation - 26
Muzzle Energy - 933-1014 ft/lbs
String 2
Browning B92
165 grain JHP
19.0 grains Blue Dot
Avg velocity - 2042 ft/sec
Max velocity - 2073 ft/sec
Min velocity - 2011 ft/sec
Spread - 62 ft/sec
Standard deviation - 19
Muzzle Energy - 1481-1574 ft/lbs
String 3
Browning B92
240 grain SWC
11.0 grains Longshot
Avg velocity - 1403 ft/sec
Max velocity - 1421 ft/sec
Min velocity - 1384 ft/sec
Spread - 37 ft/sec
Standard deviation - 13
Muzzle Energy - 1020-1075 ft/lbs
I had a great time playing with my new chrono and figured I would post some data I derived here. I figure it might help someone else out down the road.
None of the loads shown here showed any sign of being overpressured. But, use this data at your own risk and assess your results accordingly. I plan to bump up the A#9/Striker load to around 11.6 grains next to see how that does. I don't know if I will try higher on the striker/H110 loads as that is a max load shown at the Hodgdon Data Center, but with a different bullet. And I definitely will try hotter IMR4227 loads too, as that isn't a max load I shot today either and it showed no sign of pressure.