Wednesday, June 24, 2009

Reloading tip: Cracked nickel cases

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(click on the photo to enlarge)

There is some question about nickel cases and premature cracking from multiple reloading. Does it happen? A resounding.... Yes. Is it a real problem? Maybe.

The .45acp cases pictured above are of several brands, and all were found to be cracked during examination while reloading. They are in a batch of roughly 500 well used cased of about the same vintage, and have all seen roughly the same loadings.

While the nickel cases in this batch are showing cracking about five times as often as the plain brass cases, it might be worth noting the wear on the cases. This brass has been reloaded in excess of twenty times..... and owes the shooter nothing. As can be seen, it's been through the process so many times the nickel plating is actually wearing off the cases.

I take away two points from this situation:
  • I will not hesitate to reload nickel cases when I have them, and have no fears of 'short' case life with nickel.
  • I will examine nickel cases a little closer during reloading, and reserve them for mild target loads where a missed crack may not be such an issue.
Why use nickel plated cases at all, if they have even this small flaw? There are several good reasons. Chief among them (for me anyway) is that I pick them up at the range and they are free. Secondly, they resist corrosion when used in a carry/hunting pistol, and won't turn your leather gun gear a slimy green with age. Thirdly, they feed nicely in an auto-loader since the nickel plating is rather slick. Lastly, they clean up in the polisher in minutes, rather than hours.

Nickel plated bottle neck rifle ammunition is another story, and can cause reloaders to have fits. The hard nickel coating resists sizing to a point, and the higher pressures involved promote cracking at a much higher rate. They can also be a pain to trim, and are hard on the tool heads.

That said, nickel plated rifle cases are a fair choice for hunting, as they feed very smoothly and won't corrode under even the nastiest conditions. They'll have a shorter reload life than brass cases, depending on reloading method and pressure of the loads, but five or six loadings out of a single rifle cases are still possible.

For nickel plate pistol brass... the photo above speaks to that. Yes, nickel cases will crack more often, but not enough to shy away from using them. All it takes is a little more close examination as they age.

Commenter Sigivald asks a good question, and one I should have thought of myself. Exactly why do nickel plated cases tend to crack more often?

I think it has to do with the nature of nickel and brass, and their being dissimilar metals. They expand and contract at different rates, and react to sizing in different ways. One metal is trying to expand .005", while the other is attempting to go .008". The stress and strain put in place can pull metal apart.

I have read that the internal stresses inherent in the nickel plating itself leaves it stressed at 50% of it's fracture point even while sitting at rest. Add in repeated firing expansions, pressure, resizing, expanding, and crimping.... and something is going to happen. Brass is much more forgiving.

After photographing some nickel plated cases showing flaws (example above) I noticed that some cases have cracks in only the nickel plating... and not the underlying brass. This would imply flaws in the plating process, and delamination of the metals. I have to think such a crack in the plating would quickly lead to a case cracked completely through the body.



15 comments:

Crucis said...

When I was shooting 1000+ rounds of .45acp some years ago, I reloaded extensively. At the beginning, I had a case feeder and used it. It worked well. After reloading some cases as many as 10 times, I stopped using the case feeder and began examining each case as I went along. I did find some cracked cases although not as many as I anticipated. I used a Lee Progressive way back when. I now have a Dillon 550b. It's not as fast as the Lee since it doesn't auto-index and I still manually insert the brass for each round.

That's one reason why I like the Dillon. Yes, there are case feeders available, but I'll pass on them.

BTW, I don't load my .45acp to max pressure, just enough to make power factor for IDPA using a 200gr LRN bullet.

Little Joe said...

Yeah, I'm with you on this. I pick up and use any nickel cases I find at the range.

I usually find a lot of them too. Many folks just take a first glance and think they are steel cases.

I wonder why the folks that shoot them leave them behind. I gues they are not reloaders or they are not well informed.

More for me heh?

Joe

Sigivald said...

Actually, that brings to mind an interesting question.

Since it's just a very thin layer of nickel plating over normal brass, why does it crack so much more readily?

Carteach0 said...

Interesting question Sigvald, and I added it to the post, with my thoughts.

Crucis.... I too examine my cases closely. Bright lights over the bench, reading glasses on, etc.
I am convinced it's necessary and that it pays off.

AKA Angrywhiteman said...

Additional info concerning nickel plating;

http://www.varmintal.com/arelo.htm#Nickel_Brass

I was surprised at the hardness of nickel plating.

Conservative Scalawag said...

Even though I am not reloading right now,I still pick up casings,for the day that I do.

This is some very useful information here,that I didn't know about nickel casings.

Thanks for sharing.

Old NFO said...

Good points Carteach0, and agree they are great for carry/hunting! Thanks for the info!

Crucis said...

As I said earlier, if you keep the pressure down a bit, you can reload brass many times. I've some .45acp brass that I've reloaded 10 times or more. I've also some .223 brass that I've reloaded up to five times. I've not had to trim cases either. That is most likely due to the lower pressure as well.

I do clean primer pockets from time to time.

GunGeek said...

Can I assume that nickel non-bottleneck rifle cases, such as 45-70, are to be treated as pistol cases? Or should one think of them as rifle cases and plan on fewer reloadings?

Carteach0 said...

GunGeek, I have used nickel plated cases in .444 and 45/70, with some fairly stiff loadings. None gave me any problems, and all were loaded five or six times before the rifles left my hands. I suspect in either case the pressures involved were relatively low by modern standards, and the straight wall cases did not promote stretching much at all. I don't recall having to trim them past the first time.

GunGeek said...

Thanks for the info. I've got both plain brass and nickel plated for my 45-70, but off the top of my head I don't think I've reloaded any of the nickel yet. I saw somewhere, way back when, several recommendations for paying the extra to get the nickel plated ones for the 45-70 so I've got a few hundred of them.

I'll just keep a close eye on them and not worry about it too much.

AKA Angrywhiteman said...

Albert Rasch, The Rasch Outdoor Chronicles, has gotten his dander up over an online plagerist.

Here is a link to his ongoing campaign;

http://trochronicles.blogspot.com/

Robert said...

Here's why nickel-plated cases may be slightly more prone to cracking: hydrogen-embrittlement, an artifact of the plating process. Heating can drive off the hydrogen, doesn't have to be a high temp, but there is of course a risk of annealing brass, so... Why bother? You can still get plenty of reloads from nickel-plated brass without worry.

Carteach said...

Interesting! Thank you.

Mick said...

By a huge margin, the majority of my reloading is .38 Special, with 3.5 gr. of WW 231 and 150 gr. cast SWC; a moderate load, on my Dillon 450 updated with auto-prime/powder drop. I have cases headstamped as military from the 1970's that I can't quite read through, but have certainly been through the dies 20+ times. I do find splits more often in nickel cases, usually at the crimp line or case mouth, but even so, as mentioned, they owe me nothing as I've seen S&W stamped heads on nickel brass, even Super Vel, routinely. Interestingly, I've noticed I hear many splits before I look for them-- six cases in the hand have a different sound when one or more is cracked or split. This does not preclude checking them all, though!