This has been a goal of mine because the crimp on .44-40 ammo is weak because of the thin brass at the case mouth, and if you go hunting with your lever rifle, you have to load ammo in and out of the rifle every day, and after shunting the cartridges back ten times just about all of the case mouth crimps will fail and the bullets will pop back inside the cases. After three days of hunting - you've got no ammo left!
With black powder or bulk smokeless loads this is not a problem, the bullet is supported by the powder itself. So I mostly have hunted with blackpowder .44-40, or with a bulk load of smokeless consisting of H4198 or RE7. Which are good loads in themselves and solved my problem, but it always nagged at me that all the ammo manucfactures of .44-40 crimped under the bullet, Winchester, Remington, Union, Imperial Kynoch...they all did it. If I wanted to use fast smokeless powders I needed a good crimp. The faster powders also are the ones I use to make high velocity loads too, such as H4227.
Well I managed to pull it off using a little cheap pipe cutter that cost me $8.00. The idea came to me a little while back, but I thought, that will never work. Last night I thought I would try it anyway.
Here are some examples pictured - on the left are normal cartridges with a Lee crimp die crimp in the case mouth, on the right are crimped both at the case mouth and under the bullet.
These cartridges are loaded with 10 grains of Universal which gives around 1300 fps with a 240 grain bullet. There is enough space in the cartridge to hide another bullet in there, so if the crimp is going to fail these would be good contenders. I cycled these cartridges through a full tube magazine load of ten rounds making sure they were the first ones loaded in, meaning they would get shunted back through the magazine the most times, shock loading the bullet each time as another cartridge is lifted up into the action. I did this twice, which is enough to cause the failure of any case mouth crimp. They all survived with no movement! This was a success.
Now I had to shoot them and see how much trouble this sharp crimp into the body would cause the shell case itself. Perhaps it might crack at this point when I shot it. Perhaps it would not survive multiple loadings.
I went to the range and shot off my body-crimped cartridges: I shot a group at 50m just to check that nothing else was affected and got a decent group, fairly typical for this carbine with open sights and smokeless loads -
You can see here my cheap little pipe cutter. I filed the cutting wheel a little to blunt it a bit before proceeding. I had this pipe cutter for turning .30/06 brass into 7x57 brass - resizing and then I shorten the necks before trimming properly. I remembered when cutting cartridges case in this way that first it dents and crimps thin brass before it actually begins to cut. Hence my idea that it might work crimping the body of a case.
The cases themselves after firing look normal, some have a light score mark where the crimp was located. This may disappear when I resize them. But I am thinking if I can get three of four loadings out of them then they would be alright for the high velocity loads, which are all loads with smaller amounts of fast powder that do not fill the case. With a robust crimp like this I can now take these loads hunting.
I am quite pleased with myself, its taken me over ten years to figure this out and would never have believed I could have done it so well or as simply as this.
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