Author Topic: improper sizing of my brass (Read 421 times)

bluebayou · « **on:** November 05, 2005, 08:02:56 PM »

My resized brass has the "incipient case head separation" bright ring around the base of the case. This is 7-08, by the way. The ring is completely around the case. Above the ring the brass is scratched and dull. Below the ring the brass is smooth and shiny. I did not pay attention to the cases as they were removed from the die. These are the second and third firings for Remington and Winchester cases respectively. The problem was pointed out to me by a guy at the range. Some of the cases had a ring halfway around the case. This guy said that the die wasn't aligned properly when I resized. In any event he says that all of the cases should be thrown away.

At this stage should I do the paperclip test to feel inside the cases? Do cases always have a ring of some kind around them? Should I pitch all of the cases? If I pitch them all out then what am I doing wrong to get improper headspace or die marks? Could I have a die that is out of tolerance?

I realize now that I have been kind of hazy about the term "headspace". Reading up this week, I gather that the body of the brass can be too long (from base to shoulder). I had trimmed the cases to 2.035 after resizing. I guess that I could use calipers and measure the case bodies of the "ruined" brass.

John Traveler1 · « **Reply #1 on:** November 05, 2005, 08:21:38 PM »

You have apparently somehow overresized your cases. I would expect a lot more than two or three reloads in an 7mm-08 chambering. Assuming that your loads are not excessively hot, I would check the following:

If your dies are high quality (RCBS, LYMAN, Redding, Hornady, etc) it would be unlikely to be a die problem. Check your shellholder. If the shellholder is out of spec (casehead to top of shellholder 0.125", then full length sizing would OVER RESIZE your cases, resulting in an excessive headspace condition.

Remember that headspace issues involve both the ammunition AND the rifle. You could also be firing in-spec ammo in a rifle with excessive headspace.

You should definitely do the paperclip inspection to find incipient case separations.

cwlongshot · « **Reply #2 on:** November 05, 2005, 09:31:45 PM »

You may have a couple things going on here at once. As stated, this involves BOTH your reloads and your rifle.

(No insult to your intelligence meant. I am unsure of your reloading knowledge or experience)

This "ring" is a tell tale sign of head space issue. USUALLY found to be the fault of the guns chamber. It COULD be the reloaded cartridges. It is a result of your brass trying to "fill" the guns chamber. The area just above the web is where it thins, leaving the ring you are finding. Sometimes it is only a pertucular lot of brass and not a major problem. Definitely check those cases. I have a couple questions.

Is this a new to you gun? I mean you are recently shooting reloads in it. Was it purchased new or used? How do FACTORY rounds look? Has this problem ONLY found in your reloads?

Lets rule out the reloads. You will need a case KNOWN to be fired in your rifle. Now accurately measure the case. Compare the measurements to that calibers diagram in your loading manuels. If you find that the shoulder is longer than the sammi specs for that caliber your problem is with your guns chamber. For a idea of a leighway, compare other calibers you may have that are known not to have any problems. Depending on your load, this may NOT be completely accurate. If we suspect the gun, we may need to get an accurate cast of the guns chamber. This is easily done with a material called creosafe, available from Brownells and Midway. You could also force a related bullet to accurately full the chamber, by seating a overly long bullet out to firmly engague the rifling and fire it.
DO NOT DO THIS WITH A REGULAR POWDER CHARGE!!! It needs to be reduced, as we are only looking for chamber dimensions. If the case is too short it is held to the breech face by the extractor. it is slammed to the rear, upon ignition and the case is streached to the front of the chamber by the rapidly expanding gasses. But the extractor is not keeping the case against the breech and brass is somewhat elastic. Seating a bullet long forces the case against the breech, forcing the brass to flow forward, filling the chamber.

In your initial die setup, do you have firm contact between the sizing die and the shell holder? I prefer light contact, but this will be determined more specifically by your particular guns chamber dimensions. Initially, I adjust mine to firm contact, than back them out about 1/2 turn.

I have more suggestions, if you could answer my questions, I'll have a better idea of how to help. I'll check here again tonight night.

Once we know where the problem lies we can better decide on a course of action to deal with it.

CW

victorcharlie · « **Reply #3 on:** November 06, 2005, 02:30:25 AM »

Are you getting the ring with factory ammo? Have you tried neck sizing once fired brass instead of full length resizing?

PA-Joe · « **Reply #4 on:** November 06, 2005, 02:53:22 AM »

I would paper clip test the cases. Most dies can't resize the lower 1/4 inch of the case therefore there will be a small outer line and abrasion above it. This is normal.

bluebayou · « **Reply #5 on:** November 06, 2005, 09:40:59 AM »

CWLONGSHOT, the rifle is new to me from Remington. It has maybe 200 rounds through it. The factory loads (Remington Corelokt) looked fine when they came out of the gun. The Remington brass was then resized and fired with the reduced load of H4895 and with the start load of H4895. The Winchester brass has been fired a total of 3 times with varying loads of Varget and BLC-2. The ring or whatever is ONLY on my resized brass. Come to think of it the marks were on the Remington brass BEFORE I fired it the second time last week. Last week was when the guy next to me at the range looked at my brass and commented on it. BEFORE I fired it, he said that it was either a headspace problem with the rifle or that the die was cocked to one side (the 3 that he picked up had the ring half way around one side).

Let me find a paperclip and feel inside the cases. Meanwhile, any advice would be great.

John Traveler, when you say "over resize" to you mean that the cases are sized too small?

bluebayou · « **Reply #6 on:** November 06, 2005, 09:49:10 AM »

I might just be freaking myself out for no reason. Using the paperclip and lightly dragging it from the web I can't feel anything whatsoever. This may just be a cosmetic issue with the surface of the brass. Is that possible? PA Joe is implying that. I will try to upload a picture of the brass in question. Strange how you learn more when you mess things up.

Iowegan · « **Reply #7 on:** November 06, 2005, 11:40:35 AM »

When you full length resize, you're bound to get a slight ring where the web meets the case wall. This happens because the head is solid and doesn't want to compress like the thinner walls. No big deal! All rifle brass will do it when you size, even an unfired case.

In the future, use the paper clip on a few cases in the same batch before you start reloading. If you start feeling a flame cut, it's time to trash them.

jgalar · « **Reply #8 on:** November 06, 2005, 05:25:55 PM »

Without seeing the brass I would tend to agree with Iowegan and PA-Joe that the ring is just where the die isn't sizing the case. If you really want to make sure take a dremel type tool and cut a case in two.