I loaded up 50 of the 10.4 mm Italian Ordinance cartridges based on the .44-40 case. The results were fine - the pressure was low enough that the slight size differential doesn't appear to cause any problem. I was able to get some 200 grain .44-40 bullets sized to 0.425", and while they might have worked OK at that size, I built a punch to size them, using the revolver's cylinder, to the exact dimension of the cylinder throats, 0.422". This is what the finished cartridges looked like:



I loaded the cartridges with two loads, 3.5 and 3.8 grains of TiteGroup. Velocity data are shown in the regression curve below.



The preferred charge was estimated to be 4.0 to 4.1 grains. Accuracy was acceptable for a combat gun at 10 yards This is the 3.8 grain target.



The flyer at 10:00 was my first DA shot. The rest were SA. The only problem was that the POI was 8" above the POA due to the 200 grain bullet. The sights were regulated for the standard 10.4 mm bullet weight of 175 grains, and I had to sight at the bottom of the target to get the shots near the bull.

I have put this project on hold until I can find a proper bullet. The results so far have convinced me that the round and gun were adequate for their intended purpose - emergency short-range defense. Recharging the gun would not have been practical under those conditions.

Buck