I have been having some trouble lately with 9mm cases breaking in my sizing die. The die is a Lee full length carbide die. The cases have been cleaned. I never had trouble with this in the past, having put probably 3-4000 cases through it but have had three cases break in this batch of a few hundred. I never lubed with carbide dies in an caliber.
What is going on here? Is the die wearing out?
I have never heard of a carbide die wearing out. Especialy with only 3-4 k rounds. I know people who do that in a day.
How many times has the brass be reloaded? I suspect the problem may be the brass has reached it's life expectency.
2cl
A picture of a broken case would be greatly beneficial in our endeavor to diagnose the problem.
That said, I would agree with 2cl that wearing out a carbide die is unheard of, especially on 9mm brass.
Are you familiar with the provenance of the brass you are using? IE: do you know how many times it's been reloaded, what firearm it was used in, etc? Or is it 'range pickup'?
I'll try to get a picture tomorrow. The brass had the end with the primer pop off. It looks like it was fused at the factory and the union broke. I have know idea if that is how cases are actually made, but that is was it looks like.
The brass is range pick up. The three cases were all different brands; I think the last one was NATO brass. I am using a cheap Lee single stage for the size/decap, in the past I used a Lee Load Master progressive for the sizing. I have used this single stage for .380 acp in the past for about 3-500 rounds and didn't have any problem.
It doesn't seem like I am having to push excessively hard on cases, and these three didn't feel any different and they all popped off with the case fully inserted, I think they broke just as I was starting to pull the case out.
Was there any commonality in the head stamp of the cases which separated?
There is likely no way of knowing with range brass exactly what you have there as far as how many, if any, times it has been reloaded.
Its too late now to look at primers for pressure signs, but do you notice the case being a bit extra shinny in the area where it separated?
Could be fatigued brass or excess pressure or a combination of the two.
If the head stamps are the same on the cases which separated, stop using those, especially if they are oddballs.
Check the interior of the die to see if there is an obstruction and clean the die.
Probably not your issue but a carbide die will wear out sizing steel cases and even faster sizing dirty cases.
I have had this problem in R-P rifle brass before. My conclusion, was that it was just soft brass.