Getting Neck Splits on new 7.62 NATO

[Danny]

I just looked over some load testing that I had done on some USGI NEW Brass which I got some years back from Jeff Bartlett. It's RA 64 new. I was shooting it in my SA Inc. Super Match and also tried a little in my other Super Match. I'm getting some small neck splits on some of the brass on the first firing. I've never had a split neck before. The splits are just starting and are only up to about .070" long at most (approximately). It's showing splits in both rifles. I'll get about 2-3 or so splits per 10 round batch, sometimes 0, maybe more at times. I've done nothing out of the ordinary in reloading. It's just had the necks run over the expander in a die to round the necks up and has had the primer pocket uniformed and the crimp removed with my Superswage. The tar sealant had to be cleaned out of the neck and that was not simple. It was also washed after working the cases to get the case lube off, then loaded. I'm not crimping. These were to be loads for Highpower Competition. I'd say that it's going to be load once and toss, unless someone has any other ideas. I don't know if I'd try annealing. Any help with why these necks might be splitting, or whether any others have noticed this with this lot of brass would be appreciated. I'd really appreciate just about any discussion on this. It would help.

Thanks,

Danny

Information

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[Matt Anthony]

I don't think you have a choice, you have done everything correct to ensure proper loading techniques, Anneal!

[MEHavey]

Hornady's annealing system makes it both a snap and an exact science.

MidwayUSA - Hornady Annealing System

Sure seems to have gone up in price though (prev $37 or so) -- like everything else reloading/ammo -- but easily worth it if you get another dozen firings out of cases.

They've gone up in price too.

[FTIII]

Anneal them, some years ago I bought a batch of Remington .257 Roberts brass for fire forming in my .257 Ackley Imp. When fire formed and this means the first shot I got 1 in 3 neck splits, new brass. When I contacted Remington about it they blew me off. I anneal "all" new Rem .257 brass now and I do not anneal the winchester.....better brass? maybe. As brass ages it can get brittle if it's old brass....anneal it. HTH

Regards

BudT

[MEHavey]

If nervous about annealing, either get the Hornady kit mentioned above, or go directly to the folks who make the temperature indicating laquer:

Tempilaq, 175°F to 1900°F indicating liquid **

Get the 475 dgr F/(246 dgr C) solution and just use the open chuck on your cordless drill.

- Paint the cases about 1/4" down from the shoulder w/ a small swipe of the indicator (It looks/acts/goes on like typewriter correction fluid and dries brilliant white);

- Slip case inside the drill chuck (leave it very loose);

- Spin the case (low speed drill setting) in your MAP/propane torch flame centered on the shoulder/neck;

- Watch the indicator go from white to totally transparent;

- Tip the (loose) case out of the chuck and into pan of water.

(Note: the water does not affect "tempering" one way or the other. It just stops the heat from creeping down the case. Not rocket science.)

10 seconds max/case cycle time. 100-120 cases in 10 minutes. Easy.


** You can also get it at Brownell's for about a buck more. But it looks like they preferentially stock the 450 dgr F fluid. No big deal difference.

[Parashooter]

Or you could just do it the easy way, using your fingers as an overheat sensor at the head end. You'll wreck a few cases by overheating the neck but soon learn how much heat is "enough" and how to direct the flame at the shoulder, not the mouth.

[Matt Anthony]

If you want to try a different approach, this is how I learned to anneal cases for 222 Remington. Buy a quality candle! Good quality candles put out more light/hotter flame than cheaper ones, so you will spent twice as much for the quality candle.
Light your candle, roll the case into the flame just on the neck and when it feels too hot, drop it into cold water. Too much heat can ruin the case! You will get the desired effect and learn that you really don't need as much heat as you think to change the molecular structure.
As there are more scientific methods noted in this thread, this has honestly worked for me throughout the years.
Matt

[slamfire1]

New brass, dated in 1964.

Do you mean unfired brass?

Was this pull down ammunition?

[Danny]

New brass, dated in 1964.

Do you mean unfired brass?

Was this pull down ammunition?

Yes, it's actually pull down bought from Jeff Bartlett unfired. I wrote that late at night with a lot of things going on. Thanks for asking about the clarfication. It looks like I'll have to anneal....or trash the brass, which would be a sin now. Would it be too late to anneal the previously fired ones which upon inspection don't show any splitting?

Thanks for the help guys,

Danny

[slamfire1]

Yes, it's actually pull down bought from Jeff Bartlett unfired. I wrote that late at night with a lot of things going on. Thanks for asking about the clarfication. It looks like I'll have to anneal....or trash the brass, which would be a sin now. Would it be too late to anneal the previously fired ones which upon inspection don't show any splitting?

Thanks for the help guys,

Danny

Here is an alternate, unwanted explanation:

Your pull down brass may have been weakened by the gasses released by deteriorating powder.

There is a tremendous amount of denial on this, but powder deteriorates.

When double based powders go bad they release nitric acid gas. This gas will cause corrosion and will attack brass. I don’t know how, but it does.

I had surplus 4895 go bad in the case and cause green corrosion on the base of bullets and case neck cracking. Case necks are more highly stressed than the other sections of the case, and it is thin. My guess that is why the necks crack.

I have been told the Army scrapped ammunition based on clock time. It is 20 years for double based powders and 45 years for single based. Your brass may have been laying loaded far longer than it was supposed to, before it was scrapped. There is the chance the powder in the cases was just starting to go bad.

The cases with split necks, toss them. Cases without split necks, anneal the stuff, do the rain dance, cast dark magic spells; if it helps, it is worth doing.

If it does not help: you are hosed.