Lee Loader

I've done that on my LCT caused by the bullet not starting straight or the index slightly off.

Fyodor wrote:I also never heard about straight cases to elongate under pressure.

Don't know about that. I shoot a dozen straight wall cartridges between the 38 Spl and 480 Ruger and they all grow with the pressure/resize cycle.

GasGuzzler wrote:I've done that on my LCT caused by the bullet not starting straight or the index slightly off.

I've had the same happen but my experience is that the mismatch translates up through the press easily so that you know something isn't right. Even in the slightest misalignment I always find that the case has been shaved shiny at some point from the steel contact.

To me, it looks like a textbook example of being over crimped. The point here in that there being no visible crimp is that the case buckled before a crimp could be applied to the case mouth. My guess is that the case buckled because it is too long. Have you taken a measure to a sampling of cases?

When I rechecked all loaded rounds yesterday to get some good pictures, I also measured the lengths of the bent cases and a few samples of the non bent cases. Both sets vary over the full scale. Some long cases weren't bent, while some short ones were.

I really liked the idea to be able to tell the difference between a BP and a nitro round by just checking what bullet was used. But I might do some tests with my blackpowder bullets on nitro loads. Maybe it is the the missing crimp groove, that causes this. Even if I was told by several experienced reloaders, that soft lead bullets don't necessarily need a crimp groove.

Fyodor - the point that I was trying to make with regards to the crimp groove is that if you have calibrated the crimping die with a short case to be hitting the crimp groove, when you got a long case, now you would possibly be hitting above the groove getting more downward pressure on the case.

Now that I saw the picture, I've run into a similar issue when reloading 38 SPL for revolver. For a couple of cases, when I was inserting the bullet they bulged inside the die but since I was doing just a few operations on the press, I was able to notice the issue without actually crashing/bending the case.
In my case there were microscopic cracks along the case length that were not visible to naked eye but once the bullet was being pressed in, they opened up and starting jamming in the die - if I muscled thru the stroke of the press, I'm sure I would have inserted the bullet and likely bent the case.

I would check the diameter of the cases that were crushed.

jloader:

I also noticed it happening on my pro1000, but on a progressive press you can't just stop in the middle of a stroke. That would also effect sizing and flaring, and might result in a half or double powder throw.

The cases show no cracks or other damages. But you are right, I set up the crimping die with some "short" cases. That's because of the telescoping cartridges I had with some of these short cases. But the difference I measured only was less than 0,1mm (about 4/1000'').

I wasn't aware that straight wall cases also grow, I was always told they won't. I guess I'll sit down and trim a few to see if this still occurs, when it's not that hot any more.

I'm quite convinced they're overcrimped, as

How are you expanding the case to accept cast bullet?

I use the LEE powder through dies. The flare is set so the case will just so accept the bullet. I tried to find the lightest possible flaring. The bullet drops in about half a Millimeter (0.02''), and are seated without shavings

I've felt the problem with the press lever on the ones I bent in my scenarios above. Crunch, uh oh.

Fyodor wrote:I use the LEE powder through dies. The flare is set so the case will just so accept the bullet. I tried to find the lightest possible flaring. The bullet drops in about half a Millimeter (0.02''), and are seated without shavings

Sounds about right.
Are you getting any lube build up in your seating die? Usually cause short OAL but you never know.

Make smoke,

Now that I saw the picture, I've run into a similar issue when reloading 38 SPL for revolver. For a couple of cases, when I was inserting the bullet they bulged inside the die but since I was doing just a few operations on the press, I was able to notice the issue without actually crashing/bending the case.
In my case there were microscopic cracks along the case length that were not visible to naked eye but once the bullet was being pressed in, they opened up and starting jamming in the die - if I muscled thru the stroke of the press, I'm sure I would have inserted the bullet and likely bent the case.

I would check the diameter of the cases that were crushed.

I too have this problem with .38 spec sometimes and it is caused by split cases. The mouth is weaker than the shorter calibers and tends to not give the number of reloading times.
The next time you finish shooting, decap the primers and check out each case at the mouth, run your thumb/fingernail around the very top of the case and if you feel anything then inspect further.
You'll be surprised how many bad cases there are.