Test your loads
Can you give me any hints? All my full power loads jump in my FA 83. I went from 340 grain bullets to 300s just because they are shorter and will not jam the gun when they jump. I've only ever had one 44 jump and that was because it wasn't crimped.
When a bullet's brethren are fired, the gun recoils back, taking the rims of the cartridges with it. Pulling the rims back, of course pulls the whole cartridge case back. But the powder inside is not attached to anything. The bullet stuck in the front of the case is only attached to the cartridge case by friction and the crimp.
The heavier the bullets (and not because of bullet length, but bullet inertia) and the lighter the gun, the worse it is, too, so the Ruger Alaskan is worse than the longer-barreled guns and the Smith & Wesson and Taurus Titanium lightweights (large bore as well as their light J-frames) are similarly notorious for jumping crimp.
This is exactly how a kinetic bullet puller works. So, if you are not at a range, you get an idea of how resistant to crimp jump your cartridges are by using a kinetic bullet puller. Of course, it is hard to get quantitative measurements.
You never know when you have more crimp than you need. Lighter guns (less inertia & more recoil), heavier bullets (more inertia), higher velocities (more recoil) require more crimp.
You know when you have too little bullet retention (case grip by friction as well as the crimp) when you find bullets pulling out of their cases.
Do this:
Make up 11 rounds (assuming you have a six-shot revolver). Measure the overall length of at least one cartridge. Theoretically they should all be the same, but you need to measure just the one.
Load up with six rounds and fire five, making sure you do not fire the one you measured.
Load up with five more and fire those, not firing the measured one.
Take the unfired cartridge (which has now been subjected to 10 inertial impacts trying to pull the bullet out of the case) and measure its overall length. If it is the longer than it was before, you have too little bullet retention force (what we have been referring to as crimp).
If the same length, you have enough crimp or too much. Can't tell.
If you took the time to measure the length after every shot, you have more data to think about. For instance, if the cartridge overall length (COAL) increased after the first and second shots, but not at all for the next eight, you probably have enough crimp, but the location of the crimp in the cannelure could be better fit.
If it is shorter, you have a mystery.
Lost Sheep
