Copper jacket shards and rings

[cstarr3]

Hi All;

First off, a little disclaimer: I recently got a polite notice from THR moderators requesting that I stop posting experimental data that may be unsafe. So, just to be clear; the data I used in this particular instance is .44 AMP (Auto Magnum Pistol) data published in Hornady's Handbook of Cartridge Reloading, 9th Edition, and the loads stayed under published maximum (for 200 grain XTPs, I loaded up 26.2-27.0 gr of IMR 4227, the Max was 27.1 grains).

When I was cleaning my AutoMag, I found small pieces of copper, mostly in semi-circular shapes. However, one of these was actually a complete ring of copper. I am pretty sure they are copper, not brass, and so I assume that they are from the bullet jacket. I had found a couple of these copper shards at the range when shooting, but did not piece two and two together at that time. The ring has the same outer diameter as the shell case, but is not as thick (it has a slightly larger inside diameter). I have searched the depths of the internet and have found that this is not an isolated phenomenon, but has happened, albeit rarely, to other shooters.

The instances I found were generally with rifle shooters. Some were reloads, some were from factory ammo. Therefore, I conclude that this is not a problem with the particular platform or caliber I am using, but it probably is something to do with the chamber of the specific gun, a problem with the dimensions of the cartridge, or a problem with the reloading process. Many forum-goers suggested that there was a problem with the neck length of the brass, that there was too much crimp, that there was too much chamfering or not enough deburring, but there seemed to be no consensus as to the cause of the copper rings.

I have measured the Starline cases I use, and they all fall withing the trim-to length (1.293") and case length as shown in the diagram in the Hornady manual (1.298). Most of the cases were 1.295"-1.296" in length. I also triple check charge weights when developing a load (a habit I got into when loading 5.7 FN), so I don't think these are due to an accidental over-pressure round.

So, take a look and tell me what you guys think. Have you guys had problems like this before? Did you get rid of it, and if so, how? Do you know if it is a problem with the bullet, the gun, the brass... etc.?

Thanks All. Cheers!
-cstarr3

 

[philip brousseau]

the only time ive seen anything like it is seating a bullet in an unchamfered case. the case will shave a small ring of jacket off the bullet and it will be sitting on the mouth of the case around the bullet

 

[higgite]

When I was cleaning my AutoMag, I found small pieces of copper, mostly in semi-circular shapes.

I don't have an explanation nor a solution, but I am curious, where exactly did you find the pieces of copper? Chamber, barrel, magazine, elsewhere?

 

[hdwhit]

I concur with philip brousseau, those are little bits of the bullet jacket that are being shaved off by an unchamfered case mouth.

I had been on a medically-imposed hiatus from reloading for about 21 years when I took it back up again in 2014. I was recently loading some 50 grain flat base Hornady bullets into some .223 cases to use in inaugurating my new Savage Axis rifle and I noticed little rings that looked exactly like what your pictures show.

I went back and inspected all of the loaded rounds and saw that in a couple of cases, the little copper ring had not fallen off but was sitting there hugging the bullet at the top of the case mouth like some sort of collar. This proved the ring was the jacket being shaved by the case mouth.

I double-checked my written reloading procedures and didn't find anything that I had missed and so I went back to the reloading manuals and saw the bit about chamfering the case mouths. I did not have this problem on rounds loaded in the 1980's and 1990's so I must have been chamfering the cases after trimming them as matter of course and so did not have it written down as a separate step. Also, a lot of stuff I loaded in the 1980's used boat-tail bullets and they may have opened the case mouth without shaving off any of the jacket. The first thing I did was to revise my written procedures. The second thing I did was to chamfer the remaining unloaded cases which solved the problem.

I am a big advocate of written procedures and checklists for reloading as a way to stay out of trouble, but the procedures have to be accurate and complete so always check what is being done against the procedures as well as common sense - that's how I spotted my error.

 

[Schwing]

the only time ive seen anything like it is seating a bullet in an unchamfered case. the case will shave a small ring of jacket off the bullet and it will be sitting on the mouth of the case around the bullet

Yep. Same opinion here. I am surprised your aren't seeing some crushed cases.

 

[longdayjake]

You forgot to mention what type of bullet was being used.

 

[hdwhit]

I am surprised your aren't seeing some crushed cases.

Good point. I guess what "saved" me was that the inside edge of the trimmed cases were sharp as a razor and I have always raised the ram very slowly when seating bullets to let the die walls have a chance to position the bullet underneath the seating stem.

The lower dynamic forces may have kept the necks from collapsing.

That, or the brass was just particularly hard since this was the third firing for these cases.

 

[au_prospector]

I would add to ask how much of a "bell" did you place on the mouth of the case before seating?

 

[cstarr3]

Okay, awesome replies... I love it! Very helpful.

When I get a chance, I will load some bullets into cases - some chamfered, some not - and then break out ye olde bullet puller, and see if I can find a copper ring or shard hanging off of the bullet. Hopefully, the solution is just user error, which is the easiest kind of problem to correct. I love the idea of written steps, and I am kicking myself for not having thought of it myself. I'll certainly type some up before I get back onto the reloading bench. Looking at some of the new cases, they appear to have a minor lip on the inside of the case mouth. However, in defense of my stupidity, I really haven't loaded new straight-wall cases before; I have only reloaded brass from factory ammo that never needed any chamfering (speaking strictly of straight walled cartridges like the .45 ACP, 10mm, and 9x19 Luger). But this is definitely a new and enlightening experience. I'll keep you guys posted on what I find.

Thanks all!
-cstarr3

To answer some of the inquiries:
Where were the shards found?
I found the intact ring and one of the shards on the bore brush when I made a pass through the barrel during cleaning. I found another one when it fell out of the gun as I removed the upper from the lower... so I don't know exactly where it originated from. A couple of them I picked out of the magazine well when I removed the grips, and another one was actually in inside the chronograph bag that had been sitting next to me when I was firing, so I suppose it was ejected with the case.
Have I seen crushed cases?
No. Not even one. If I had, I probably would have had pause early on about continuing to reload as I was. But now that I know that is possibly a symptom of this problem, I will keep an eye out for it in the future.
What bullet am I using?
I am using Hornady 200 gr. XTPs. Given that the comments agree that the problem is with the case mouth, I assume that any jacketed bullet would have the same problem. If chamfering the mouth doesn't do the trick, I might switch to something else, like a 200 gr. Nosler JHP, or a 240 gr. XTP.
How much do I bell the neck?
I open it up enough to allow the bullet to slide in a little less than 1/8". That is a tad more than most of the cartridges I load for; I usually just expand until the bullet's base can pop into the case. I'll attach a picture of a bullet, a case, and the extent to which it can be manually pushed in without needing to be wrestled to get it out again.

 

[cstarr3]

I went ahead and loaded up some empty cases with bullets, seated/crimped them, and then pulled them. I found no copper rings in the puller, and there were no indications of rings of copper being pulled off the bullets.

Nevertheless, I made sure to chamfer the cases when I started working up a new load (using Hornady No. 9 data, 25.8gr. - 27.0 gr. in 0.3 gr. increments, 200 gr. XTP bullets, new Starline Brass -chamfered this time- and CCI 350 primers). Hopefully, the problem will go away, and everyone lives happily ever after.

Again, thanks for the wonderful advice. You guys are awesome!