Well, I wanted to know what the maximum published loads for 10mm would do at the range with six different powders suitable for the cartridge, so I loaded five rounds with the same charge for each of the six powders, then went to the range with my ProChrono Digital to clock what I had loaded.
All charges were weighed because these were maximum loads, all cases were Starline, primed with CCI #300 large pistol primers, with 155 grain Speer TMJ bullets seated at 1.260", and the temperature that day (yesterday) was in the mid-to-high 80s.
I was startled by the performance I was getting, and here are the numbers.
The powder and charge are listed first, followed by each of the five muzzle velocities, the average muzzle velocity, the Extreme Spread, the Standard Deviation, and the average muzzle energy:
13.0 gr. AA#7 - 1596 + 1598 +1602 + 1602 + 1596 - 1598 Avg. - 6 ES - 3 SD - 879 FPE Avg.
7.2 gr. Titegroup - 1596 + 1608 + 1606 + 1600 + 1600 - 1602 Avg. - 12 ES - 4 SD - 884 FPE Avg.
9.2 gr. CFE Pistol - 663 + 1628 + 1626 +1624 + 1629 - 1627 Avg. - 911 FPE Avg.
11.3 gr. HS-6 - 1638 + 1654 + 1650 + 1652 + 1656 - 1650 Avg. - 18 ES - 7 SD - 937 FPE Avg.
6.4 gr. 700-X - 1660 + 1658 + 1658 + 1660 + 1662 - 1659 Avg. - 4 ES - 1 SD - 948 FPE Avg.
16.0 gr. AA#9 - 1687 + 1685 + 1685 + 1683 + 1687 - 1685 Avg. - 4 ES - 1 SD - 977 FPE Avg.
Below is a string of 20 shots fired with the 16 grains of AA#9 loads that I wanted to see for how the heated up barrel would affect velocities, which it clearly does, as you can see below:
16.0 gr. AA#9 - 1707 + 1707 + 1713 + 1716 + 1716 + 1713 + 1711 + 1711 + 1711 + 1709 + 1724 + 1722 + 1722 + 1722 + 1724 + 1724 + 1727 + 1729 + 1724 + 1724 - 1729 High - 1707 Low - 1717 Avg. 22 ES - 7 SD - 1014 FPE Avg.
The only anomaly is the first velocity figure for CFE pistol (663), which was obviously an error because the gun recoiled identically to the other loads that followed with that charge level, but that's also why I left out the extreme spread and standard deviation numbers for that one powder.
I went into this expecting to get in the 1400 FPS level, but, as you can see from looking at the numbers, these muzzle velocities are incredible, with not one below the high 1500 FPS level!
It's also clear that the barrel heating up for the final string of 20 loads charged with AA#9 increased velocities by a fair bit.
Just for the hell of it, here is a photo of the ProChrono Digital's display for the high velocity number for that string:
I was particularly interested in what the brass looked like, especially in what the primer looked like, inspecting each case for flattened, cratered, or blown primers, there was no evidence of that either, as you can see from this photo of the recovered brass looking down at the primers:
What do you folks think of all this?
Are these safe, or do I need to reduce significantly?
I mean, I was stunned to see that I was getting an average muzzle energy with that final shot string of 20 loaded with AA#9 of over 1000 foot pounds.
All charges were weighed because these were maximum loads, all cases were Starline, primed with CCI #300 large pistol primers, with 155 grain Speer TMJ bullets seated at 1.260", and the temperature that day (yesterday) was in the mid-to-high 80s.
I was startled by the performance I was getting, and here are the numbers.
The powder and charge are listed first, followed by each of the five muzzle velocities, the average muzzle velocity, the Extreme Spread, the Standard Deviation, and the average muzzle energy:
13.0 gr. AA#7 - 1596 + 1598 +1602 + 1602 + 1596 - 1598 Avg. - 6 ES - 3 SD - 879 FPE Avg.
7.2 gr. Titegroup - 1596 + 1608 + 1606 + 1600 + 1600 - 1602 Avg. - 12 ES - 4 SD - 884 FPE Avg.
9.2 gr. CFE Pistol - 663 + 1628 + 1626 +1624 + 1629 - 1627 Avg. - 911 FPE Avg.
11.3 gr. HS-6 - 1638 + 1654 + 1650 + 1652 + 1656 - 1650 Avg. - 18 ES - 7 SD - 937 FPE Avg.
6.4 gr. 700-X - 1660 + 1658 + 1658 + 1660 + 1662 - 1659 Avg. - 4 ES - 1 SD - 948 FPE Avg.
16.0 gr. AA#9 - 1687 + 1685 + 1685 + 1683 + 1687 - 1685 Avg. - 4 ES - 1 SD - 977 FPE Avg.
Below is a string of 20 shots fired with the 16 grains of AA#9 loads that I wanted to see for how the heated up barrel would affect velocities, which it clearly does, as you can see below:
16.0 gr. AA#9 - 1707 + 1707 + 1713 + 1716 + 1716 + 1713 + 1711 + 1711 + 1711 + 1709 + 1724 + 1722 + 1722 + 1722 + 1724 + 1724 + 1727 + 1729 + 1724 + 1724 - 1729 High - 1707 Low - 1717 Avg. 22 ES - 7 SD - 1014 FPE Avg.
The only anomaly is the first velocity figure for CFE pistol (663), which was obviously an error because the gun recoiled identically to the other loads that followed with that charge level, but that's also why I left out the extreme spread and standard deviation numbers for that one powder.
I went into this expecting to get in the 1400 FPS level, but, as you can see from looking at the numbers, these muzzle velocities are incredible, with not one below the high 1500 FPS level!
It's also clear that the barrel heating up for the final string of 20 loads charged with AA#9 increased velocities by a fair bit.
Just for the hell of it, here is a photo of the ProChrono Digital's display for the high velocity number for that string:
I was particularly interested in what the brass looked like, especially in what the primer looked like, inspecting each case for flattened, cratered, or blown primers, there was no evidence of that either, as you can see from this photo of the recovered brass looking down at the primers:
What do you folks think of all this?
Are these safe, or do I need to reduce significantly?
I mean, I was stunned to see that I was getting an average muzzle energy with that final shot string of 20 loaded with AA#9 of over 1000 foot pounds.
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