Case Marks Help

Hello,
I am curious if the marks on my (winchester factory) fired .30-06 cases are normal. I am uneasy with the "step" that forms right at .245" inches up from the bottom of the case. The "step" is big enough to feel with your fingernail and only encompasses about two thirds to three quarts of the circumference. I am worried that there might be excessive head space causing this. I stuck clear packing tape to the bottom of a new round and cut off the excess. On the new factory ammo I could still close the bolt after 3 layers of tape, but it would not close with 4. With a piece of once fired brass i could close the bolt with one layer of tape but not with two. If it is related to excessive head space I think i should be able to adjust It as the gun uses a barrel nut exactly like a savage. Tell me what you guys think please!!

Regards,

Trapped

Definitely don't look right to me.

Possibly headspace or case support issue(??).


Definitely pick up a set of gauges for '06 and see where you stand.

http://www.brownells.com/gunsmith-t...ace-gauge-kit-sku184-000-040-26876-52455.aspx

Yea, I will go ahead and order them. Any one else out there with experience in this kind of stuff?

Tell us about the rifle

Its a Remington 783, so far its been a pretty good shooter grouping 1" three shot groups. I did a review here.

http://www.mdshooters.com/showthread.php?t=127325

Chamber body is slightly oversize or brass is undersize. That is all. The reason it is not evenly expanded over the entire circumference is that the case was laying against the side of the chamber as pressures increased to normal peak, probably held there by the spring loaded ejector.

The 'step' occurs at the junction of the non-expandable solid case head and the expandable case wall, and simply shows us where the case could no longer expand to fit the oversize chamber.

If it were from an older rifle, I'd say someone polished the chamber rather over zealously, but being a newer gun, I'd have to say the chamber is a bit sloppy, even for a Remington.

This is NOT a headspace issue. That is quite clear from the very well done photos.

Excessive headspace allows the primer to back out from the primer's own explosion, then as pressure builds, the unsupported primer cup expands slightly, then the case is stretched as the head is driven back around the primer. This action flattens the primer and the radius at the edge is lost, and also shows the stretch result as a brighter colored, but dull textured ring just above where the solid case head joins the thinner case wall junction, just above the step, in this instance.

There is no evidence of stretching, and no evidence of primer flattening, and so there really is nothing in the photos to support a theory of excessive headspace.

Thank you for the detailed explanation E. Shell!! I have been feverishly searching the forums and I agree with what your saying. I can wiggle a new round back and forth a little bit in the chamber so I am fairly positive its just a bit oversized/undersized. Looks like i will just be neck sizing when i reload until the case streches enough to warrant FL sizing.

If that were my new rifle... it would be going back to the manufacturer for a new barrel with a properly machined chamber... AND I would send a few shells back with it to show the issue is a chamber that is cut too big.

Those cases are going to continue to expand until they separate.

I hope they fix it for you and the next one shoots as tight as (or better than) that barrel did.

RoadDawg said:

If that were my new rifle... it would be going back to the manufacturer for a new barrel with a properly machined chamber... AND I would send a few shells back with it to show the issue is a chamber that is cut too big.

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This is reasonable, the chamber should not cause brass damage, but most manufacturers disavow the use of handloads anyway, so there is no real complaint if the case doesn't approach failure at the first firing. SAAMI conformance is also voluntary. Each manufacturer has their own QC standard and they may say that "it's within spec". Remington chambers most of their barrels on a mandrel anyway, so I'd suspect their "spec" is pretty wide.

Those cases are going to continue to expand until they separate.

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Unless they are resized excessively as to extensively rework the brass diameter, they'll be fine. They are not stretching laterally due to headspace, which is what separates case heads.

The OP's idea to neck size would work if the rifle is not going to be returned, and they can also be partially sized in a full length die to permit smooth function without developing excessive clearances.

I hope they fix it for you and the next one shoots as tight as (or better than) that barrel did.

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Yep. Be worth a try, but while not ideal, it's not an unsafe condition. Again, I'd not be surprised at all if Remington told the the OP it was fine.

Buy a pair of cheap dental picks for dogs - one used to scrape tartar. Use the narrow one. Insert it in the case mouth and run it up the side of the case. If the case is thinning above the head, you will be able to feel it easily. If not and the pick runs up the side with no discernible indent, then you're fine. But, those cases look stressed to me.


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E.Shell said:

This is reasonable, the chamber should not cause brass damage, but most manufacturers disavow the use of handloads anyway, so there is no real complaint if the case doesn't approach failure at the first firing. SAAMI conformance is also voluntary. Each manufacturer has their own QC standard and they may say that "it's within spec". Remington chambers most of their barrels on a mandrel anyway, so I'd suspect their "spec" is pretty wide.Unless they are resized excessively as to extensively rework the brass diameter, they'll be fine. They are not stretching laterally due to headspace, which is what separates case heads.

The OP's idea to neck size would work if the rifle is not going to be returned, and they can also be partially sized in a full length die to permit smooth function without developing excessive clearances.Yep. Be worth a try, but while not ideal, it's not an unsafe condition. Again, I'd not be surprised at all if Remington told the the OP it was fine.

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I agree... But when I spend my money on something new... I will demand that it be right or be returned. The new rifle should not have such a sloppy chamber that it resizes or reshapes the cartridge case like that one does.

For me, sub par is not acceptable in a new piece of equipment that I did not pay a sub par price for.

Abulg1972 said:

Buy a pair of cheap dental picks for dogs - one used to scrape tartar. Use the narrow one. Insert it in the case mouth and run it up the side of the case. If the case is thinning above the head, you will be able to feel it easily. If not and the pick runs up the side with no discernible indent, then you're fine.

Click to expand...

This is a good suggestion for picking up wall thinning due to lateral stretching, but that is not at all what we are looking at here.

But, those cases look stressed to me.

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They may look "stressed" to you, but they are not. Use the available facts for your analysis. If you want to see "stressed", examine some machine gun brass.

Again, we are NOT looking at case wall stretching due to headspace, which is what promotes wall thinning. TRY to escape this unproductive thought
pattern. Headspace appears to be just fine. If headspace was excessive, then we would have stretched the case and that would show as an entirely different appearance as described above and can be readily seen in almost any reloading manual. There is NO lateral stretching, thus there will be no thinning at the web, thus there will be no case head separation, thus feeling around with a dental pick will reveal nothing.

We are looking at a few thousandths difference between the case head diameter and case body diameter. Headspace is measured on the other axis. There are tolerances. The case head must be small enough to fit the smallest chamber, and the brass body is designed to expand to fit larger chambers. Look at the OP's pictures again and notice that this is what has happened.

NO, the situation is not ideal, but there is no danger here now. The expansion is not structural damage, and is not really an issue unless we use our sizing die to bring the case back down to minimum, then blow it back out, then size it to minimum, then blow it back out. That is how we could damage the case and develop a safety issue.

Please, just LOOK at this (borrowed) photo for a second:



Can you guys SEE the thin bright ring on these cases that show the area being stretched? Sure you can, and the top three cases are most obviously damaged in this manner.

Can you see the area of the case body that expands to fit the chamber? Yes, it it the entire brightly burnished case wall area, all the way down to the solid head. This is EXACTLY where the OP's brass has shown the expansion transition, NOT to be confused with lateral stretching.

Can you see the appearances and locations differ greatly? Of course you can, and this is my point. You are clearly NOT looking at stretch marks in the OP's original photos.

Honestly guys, your suggestions about how to look for incipient case head separation are valid and useful, and your concerns for safety when this occurs are prudent and reasonable, just not at all applicable to this situation.

To suggest tests and remedies for case stretching is like complaining that your apple juice doesn't taste like orange juice. Stop for just one second, ACTUALLY look at it and think about it: It's apple juice and not orange juice at all.

E.Shell said:

This is a good suggestion for picking up wall thinning due to lateral stretching, but that is not at all what we are looking at here.



They may look "stressed" to you, but they are not. Use the available facts for your analysis. If you want to see "stressed", examine some machine gun brass.



Again, we are NOT looking at case wall stretching due to headspace, which is what promotes wall thinning. TRY to escape this unproductive thought pattern. Headspace appears to be just fine. If headspace was excessive, then we would have stretched the case and that would show as an entirely different appearance as described above and can be readily seen in almost any reloading manual. There is NO lateral stretching, thus there will be no thinning at the web, thus there will be no case head separation, thus feeling around with a dental pick will reveal nothing.



We are looking at a few thousandths difference between the case head diameter. There are tolerances. The case head must be small enough to fit the smallest chamber, and the brass body is designed to expand to fit larger chambers. Look at the pictures and notice that this has happened.



NO, the situation is not ideal, but there is no danger here now. The expansion is not structural damage, and is not really an issue unless we use our sizing die to bring the case back down to minimum, then blow it back out, then size it to minimum, then blow it back out. That is how we could damage the case and develop a safety issue.



Please, just LOOK at this (borrowed) photo for a second:

Can you guys SEE the thin bright ring on these case that show the area being stretched? Sure you can, and the top three cases are most obviously damaged in this manner.



Can you see the area of the case body that expands to fit the chamber? Yes, it it the entire brightly burnished case wall area, all the way down to the solid head. This is EXACTLY where the OP's brass has shown the expansion transition, NOT to be confused with lateral stretching.



Can you see the appearances and locations differ greatly? Of course you can, and this is my point. You are clearly NOT looking at stretch marks in the OP's original photos.



Honestly guys, your suggestions about how to look for incipient case head separation are valid and useful, and your concerns for safety when this occurs are prudent and reasonable, just not at all applicable to this situation.



To suggest tests and remedies for case stretching is like complaining that your apple juice doesn't taste like orange juice. Stop for just one second, ACTUALLY look at it and think about it: It's apple juice and not orange juice at all.

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Try to escape being a knucklehead by explaining what you see in a manner that is not extremely condescending and people will pay attention to what you say and actually learn what you have to share. I got through the first few sentences of your post and then just skipped the rest. You may be right but I didn't learn anything from you because your tone was completely douchey.


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I appreciate everyones input but i do agree with what E. Shell is describing as whats going on. I picked this case to analyze because it was one of the worst looking so Im fairly sure the case is on the small side to begin with. Roaddawg - If it weren't shooting as well as it is I would send it back but for now im content with its performance. Criterion is coming out with hand lapped match grade barrels for the 783 soon. I plan on installing one of those on the gun when they are available which should remedy the "case marks" issue.

Abulg1972 said:

Try to escape being a knucklehead by explaining what you see in a manner that is not extremely condescending and people will pay attention to what you say and actually learn what you have to share. I got through the first few sentences of your post and then just skipped the rest. You may be right but I didn't learn anything from you because your tone was completely douchey.


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Well Grasshopper, You should go back and read the entire post, You will learn something.
If you think Mr Shell was being condescending, Wait until you meet Clandestine and the Ferret.

coopermania said:

Well Grasshopper, You should go back and read the entire post, You will learn something.
If you think Mr Shell was being condescending, Wait until you meet Clandestine and the Ferret.

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Maybe that stress was caused by someone's head? :-p


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Abulg1972 said:

Maybe that stress was caused by someone's head? :-p


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137 posts and you still have not said much, Get along little boy and go and play in the firearms costing less than $ 129.00

coopermania said:

137 posts and you still have not said much, Get along little boy and go and play in the firearms costing less than $ 129.00

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Lighten up Frances.

http://youtu.be/C6cxNR9ML8k



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Abulg1972 said:

Try to escape being a knucklehead by explaining what you see in a manner that is not extremely condescending and people will pay attention to what you say and actually learn what you have to share. I got through the first few sentences of your post and then just skipped the rest. You may be right but I didn't learn anything from you because your tone was completely douchey.


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Just a thought, here........

Mr. Shell is a highly respected man and member of this forum.

In no shape, fashion or manner, does he give the appearnce or indication of being 'a knucklehead'.

The man is VERY well versed in shooting and reloading.

I strongly suggest that you take a step back, read again, and absorb as much as you can, from E. Shell.



Coming into the forum and starting the name-calling won't endear you to very many people, here.

byf43 said:

Just a thought, here........

Mr. Shell is a highly respected man and member of this forum.

In no shape, fashion or manner, does he give the appearnce or indication of being 'a knucklehead'.

The man is VERY well versed in shooting and reloading.

I strongly suggest that you take a step back, read again, and absorb as much as you can, from E. Shell.



Coming into the forum and starting the name-calling won't endear you to very many people, here.

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Even for those who rarely seek advice from others, his posts are extremely informative, but when I start reading I begin to feel like Chris Farley in Almost Heroes.