As I reported last week I was trying to make some very light loads in .40 S&W for new shooters. I made up 200 rounds with the 180 grain Rainier FP over 3.9 grains of Bullseye with an OAL of 1.131”. On Christmas day, while at Brother Doug’s place I shot some over the chronograph. This load yielded a mean velocity of 825 fps (standard deviation of 9.6 fps) for a Power Factor of 148.5. The expected result was 800 fps for a PF of 144. Not too far off from the actual. I would have preferred it be on the low side instead of the high side but still, not bad.
My typical handloads run about 940 fps for a PF of 169 or so. 180 grain factory loads run about 1000 to 1025 fps for PFs of 180 to 185. Hence these new loads are have about 80% of the momentum of a factory load and a little under 90% that of my usual handloads. This is better but I would like to do better still.
While in Idaho this weekend I bought a pound of Clays from Alan B. I loaded up 100 rounds of the 180 grain Rainier FP over 3.0 grains of Clays. I ran them over the chronograph today. Remember that the reloading manual said to expect:
180 grain bullet over 3.0 grains Hodgdon Clays => 727 fps with 131 PF
The result was 728.11 fps (standard deviation of 8.8 fps) for a PF of 131.06. Wow! That was freaky close compared to the expected result.
That gives me a load with about 78% of the momentum of my typical handloads and a little over 70% that of a factory load. And get this, it’s right at the same momentum as a typical 147 grain 9mm round but with a muzzle velocity that is about 100 fps less. That is even less velocity than a typical 230 grain .45 ACP. With such a low muzzle velocity it is much more of a push than a “snap” on the recoil. It’s a very comfortable load to shoot.
Thank you Mike B. and Alan B. for the Clays powder. That made a big difference.
I was thinking ahead to how to make a self-defense load with similar recoil properties and found that Speer makes a bullet they call Gold Dot Short Barrel for good self-defense characteristics with lower velocities. This sounds like just the ticket for Cherie. We have another range trip planned for the end of next month to do some more training and test out the new loads.