Neck Splits and General Case Life

[poguetx]

I just finished resizing about 200 spent brass cases and scrapped about a half dozen that had neck splits. Granted, some of these were probably through their 3rd or 4th reloadings, but I was wondering what is the reasonable expectation of the number of reloadings that a Grendel case can take before they show that kind of problem?

I know some of you guys are very diligent about sorting your brass and marking the number of reloads each piece has been through, but that has never been me. But I am diligent about inspecting each piece after it comes out of the sizer, which is how I found these. Obviously, I use a single stage press, not a progressive.

FYI, these were shot both in an AR and bolt gun.

[Tex74]

What brand sizing die or you using ?
I get 7-8 reloads out of my hornady brass before primer pockets get loose.

[Klem]

Pogue,

Unusual that your neck splits occur before signs of lose primer pockets or incipient case separation. Your die might be crushing the neck narrower than it needs to be.

What is the neck tension you get (measure the OD of a loaded neck, minus the OD of a sized neck)? What brand of die is it?

Do you run a bent paper clip up and down the inside feeling for the first signs of case separaton? If your necks are being squeezed too much your body might be too.

I use Lapua and have yet to throw one out, so over 10 for sure. I saw someone with a 308 case get a partial case split around the web. He says he reloaded it 20 times. That's definitely too many.

[LRRPF52]

[poguetx]

Lee dies and Hornady brass. I use One Shot for the lube. It was a mix of Hornady factor loaded brass and what started as Hornady virgin brass, but that has been through at least one reload before. The few that split looked like they were some of the older pieces, as the necks didn't polish up as well as others after tumbling. I was not able to remove the primers on a couple of the factory cases. Looks like they may have been crimped, but all the other primers popped out as expected. I do have a go-nogo gauge, but don't check each piece - just a few at the start to make sure I have the sizing die seated correctly. When I was at the range, I did find one that was split after firing, so I don't think it's caused by an undersized die, just fatigue after many reloadings.

[Tex74]

Stressed brass from combination over sizing brass and lee dies, is my best guess. Lee dies are hard on brass Overworked

[tdbru]

if you continue to get neck splits, consider neck annealing every 3rd reload or so. just a thought. though as posted above, you probably have something other to look into first.
-tdbru

[Klem]

Pogue,

Lee dies expand and contract the neck more than necessary. If you type Lee into the forum search engine you will find others in the same situation.

Case splits and separations occur gradually over the life of the case. How long your cases last depends on the quality of brass and load, but if you are crushing the life out of cases with a Lee then they wont last as long as they could.

You mention a GO/NO-GO gauge. I think you mean a rifle gauge. I would be careful using rifle guages if you don't have a good idea as to the dimensions of your chamber. By using the rifle gauge as a reference you still may be bumping those cases too much. As 52' advises, get a Hornady comparator gauge which is a more useful tool. First get an idea of the dimensions of your chamber. To do this measure the base to shoulder of a spent case. Then adjust the die so sized cases are .002"-.003" less than the spent case. This is the minimum bump needed to be reliable in an auto loader. Use only .001" for bolt guns. More than .003" will still be safe to a point, but will be flogging cases more than needed and to an early retirement.

This is the hornady gauge and what we're talking about...


The example with the rifle gauge shows how the gauge will encourage you to bump your cases more than necessary. It's great as a ready reckoner but measuring the numbers with a set of calipers is more precise, and safe.

While you get around to getting the Hornady gaueg you can use a poor man's DIY with a 9mm case. Just make sure the primer is out and the mouth is not dented. It's a bit fiddly but works.

[SCJim]

You are overworking the brass. Either one of two things are occuring. The die may be squeezing the neck down too far then the expander ball is stretching it back out. The other cause would be a sloppy chamber and the neck is expanding more than normal on firing. Take a measurement of a fired case neck before sizing and then after sizing. Then seat a bullet and take a third measurement. Take those three measurements and post them and I can give a more accurate reply. Either frequent annealing or a good bushing die used with the proper size bushing with the expander ball removed may cure the problem as long as it is not a sloppy chamber issue