necks split

[Ben]

I've had several ( 8 or more in the past 2 months ) F-C commercial 30-06 and 308 Win. necks split of late.

Is it just me or have others of you experienced this ?

My Rem. and Win. cases don't display this problem.

Ben

[lwknight]

Are you talking premature splitting or cases that have been cycled a lot of times?
Eventually they all will split. You can reduce the neck splitting by annealing and deburring.
Deburring is just as important as annealing.

[Ben]

No these are not fatigued cases, they are fairly new with 3 - 4 firings.

Fired in different rifles, same splits, all cases that display this are Federal.

I'm beginning to think Fed. let some brittle brass out of their plant.

[runfiverun]

i have had cases with the factory squish crimp [3-4 rectangular] on them split in the first reload.
i have had to trim some almost all the way to the bottom of the rectangle to avoid it happening.
i recently had this happen on some winchester 308 brass,rather than trim them all that short i annealed the whole batch and i'll see how that goes.

[smoked turkey]

Ben recently I acquired a .416 Rem mag and some new unfired brass. It is Remington brand. On initial sizing I had a neck split on me. I am lubing the inside of the case lightly with graphite and I have the sizing die backed up so as to just stop short of the case shoulder. I am wondering if brass gets harder and more brittle just through ageing? This brass though new appears to be new old stock. In an effort to experiement a bit I annealed 10 cases and left 10 untouched. I am going to do some development on those 20 cases to see if annealing made any difference in case life. I suspect that your cases would benefit from annealing.

[Ben]

smoked turkey,

Probably could benefit from the annealing. Seems odd that my other cases don't display this , only Federals.

[mac60]

This isn't the first time I've heard that complaint about f-c brass. I've never experienced it myself, but I use very few (if any) f-c cases. At any rate I anneal any bottleneck case I use every few firings.

[Ben]

mac60

This isn't the first time I've heard that complaint about f-c brass.

Well, .....that does make be feel better. I couldn't see anything different that I was doing ....one case brand vs. the other.... I think I may well begin to avoid Fed cases.

Ben

[runfiverun]

brass does harden with age.
ever wonder why sometimes ammo just a few years old isn't as accurate as the initial testing was?

[mac60]

runfiverun makes a good point. It's possible it sat for a good long time (under other than ideal storage conditions) before it came to you, so that may have something to do with it. I highly doubt it's anything you're doing though Ben.

[hithard]

That F-C stuff is a bit on the tender side. I've never had it last as long as anything else. Look at all the once fired brass outlets. You will see that federal is always long in stock after the other brands. There is a reason for this. Alot of times you can even get it cheaper.

[Ben]

Umm, maybe all the companies make a bad run every now and then ? ?

[tomme boy]

Federal is my favorite brass in 308w. It has always shot better than others. I think it is partially because of the thicker necks. The weight of the cases seem to be very consistent also. I have had splits from every brand made. Even the expensive Lapua brass.

[JIMinPHX]

I sort of hate to even ask an obvious question like this to someone with your experience, but have you measured the OD of the case neck of the loaded cartridge & compared it to the ID of the chamber in the neck area?

[GP100man]

Ben , I had a batch of F-C 30-30 brass that was 2x fired & loaded it up & went back 6 weeks later only to find a 1/3 of em had split , just sitting loaded !!

I just recently prepped 2 different batches of 243 brass & the F-C was much harder to trimm or actual cut with my RCBS Trimm Pro, also when chamfering the tool would chatter .

Thinking of annealing this before loading it.

[tomme boy]

Unless something has changed, Federal brass has always been softer than the others. Being that brass an ammo has been in such a short supply for the last few years, it may have been outsourced to another company. I know Winchester does this. Maybe Federal has done it as well.

[Ben]

On my end of things here, I just can't see that it is something that I'm doing wrong.

I think F-C has shipped some brittle brass. Remember this is going on in multiple calibers, as you can tell by reading the post above.

Ben

________________

JIMinPHX :

Remember that I mentioned that this was going on in 308 Win. and 30-06 in a variety of rifles.

Ben

[stocker]

I had a gent I think is a metallurgist climb all over me when I referred to age hardening of cartridge brass. Not in a million years according to him. He says the biggest cause of brass failure is actually due to normal stresses that are present in the metal being affected by contaminants whether air borne or direct. In particular I think it was ammonia contained in many bore cleaners we use in our shops and contaminants in card board storage containers (ammo boxes). I've probably repeated the same reasons for brass failure as most guys do many times but I had to search and could not find a source that would confirm my beliefs. His qualifications far exceed mine so I have no rebuttal to his comments. He had similar words regarding work hardening of brass and I think the term he he referred me to was stress corrosion that causes splits. He referred to brass that had been reloaded many times over a short period of time with no failures. I have also done this with no failures. But, brass which is exposed to some contaminants will fail over time.

[stocker]

The previous post does not mean to ignore proper annealing of brass to begin with, just that other things than I commonly believed to cause splitting may not have been valid no matter how often they may be repeated.

[Idaho Sharpshooter]

Technical Answer: the mfgrs hold a certain tolerance in case manufacture. It takes 6 steps to turn a sheet of alloy to a cartridge case.

1. Big rolls of alloy get put on a roller (unroller?) and run thru a machine that stamps round blanks.

2 & 3. Those blanks go thru a couple of stamping operations and become cups.

4 & 5. A couple of forming dies and the cups become cartridge cases. At one time, the mfgrs
annealed the brass to soften it after step 3, since every step in the forming process hardens the
brass.

6. Once upon a time they trimmed the brass to final length and finish annealed it. Now, most, Starline being the worst offender, they skip that step. This produces brass harder than woodpecker's lips.

Due to production tolerances in the process, the case is almost never uniform in thickness.
If you have or can borrow a ball head tubing micrometer and measure a dozen or so out of a box/bag of 100 new bottleneck rifle cases; you will find up to .003"-.005" variance in the neck thickness. Norma and RWS do not allow slop to develop during their process.

When you load a round and fire it, you may produce in excess of 50,000 PSI. The case neck expands to fill the chamber, and that pressure causes the case to stretch. The thinnest part of the case neck stretches farther. This further thins it. Do that two or three times, without annealing the case neck, and you begin to get splits.

Sloppy case tolerances is a bad habit the ammunition companies have picked up from their military contracts the past thirty years, along with minimum specs on the thickness of the case, and the length.

Rich
Sua Sponte