Over the years, Ive had a number of ties ups due to crimp jump, or the bullet moving forward under recoil. All the bullet needs to do, is get past the front of the cylinder just enough that it wont clear the end of the barrel, and your dead in the water.
"Crimp", or proper crimp, also seems to be more of an issue with revolver rounds and problems. Its more of a reloading issue, but its still an issue, and part of the "jump" issue, as well as squibs, or squib related problems. The issues here between revolver and auto are usually just the opposite too.
Another issue Ive had here, that I also believe were due to bad or at least inconsistent crimps, was having the primer ignite on firing, and not igniting the powder charge, yet the power of the primer, was enough to push the bullet into the forcing cone, tieing the gun up, requiring you to have to hammer the bullet back into the case to get the gun open. The powder showed signs of starting to light, but never did.
Now, in the above case, the powder was fresh, as were the loads, and the same powder and primers, were used in both 357MAG and 9mm loads, and all shot on the same day. For some reason, the actual "problem" cases always seem to happen with nickel 357MAG cases, although I have heard and felt the problem with both 38 and 357's in other instances, regardless of brass color, but most still fire. Never been a problem with the auto cases.
Most of the times when I do see the above issue its usually in colder weather, and especially when the rounds have been in the cold for a while. I shot 200 rounds of 38 the other day, when it was in the upper 20's, and had a few "soft" rounds in the lot. They all fired, but you could hear and feel the difference in the rounds when they went off.