Case Head Bulge ?

Norseman79

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Ok,

So, I am hoping to figure out if this is normal or not. I have a Tikka rifle in 30-06. It by far is my favorite hunting rifle. I've had it for about 7 years. I have kept most of the brass from shooting factory rounds, little over 250 cases. I am looking to reload them, and I notice something odd to me. Just up from the head of the case, there is a raised ring over around 1/2 of the case. I have included a pic. This is not present on the new unfired factory cartridge. This ring is on all once fired brass, regardless of manufacturer. This seems to have been an issue from day one, but it's hard to see unless you're inspecting it closely. I have reloaded some in the past, never ran across this before. I'm assuming a full length resizing die might work the brass a little hard and reduce it's life due to the buldge?

So, is the chamber loose?

Are these safe to reload?

Why is it only on 1/2 of the case?

Any thoughts or wisdom would be appreciated.

Thanks,

Dan


3006.jpeg
 

MechaNik

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In 7 years you've only shot it 250 times???

Without holding it in my hands, I would suggest you have a mild imperfection in the chamber but none I would worry about. Or it's just the way tikka chambers are, much like Glock pistols. I can't see why you wouldn't be able to safely load these unless the "bulge" is more like a mountain peak than a rolling hill.
 

po18guy

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The pic does not look bad - normal, actually. Couple of things. Remember that factory ammo is on the small side of specified tolerance, as it has to fit all chambers. Drop a loaded cartridge into the chamber and note that you can wiggle it with your finger. Secondly, the bulge coincides with the transition from case web to the wall of the case. The brass is naturally thinner there, so it fireforms to the chamber. The rest of the case is equally expanded and everything but the head is resized in reloading, as the head does normally expand. Unless this miked out to .020" larger than the head or some excessively large number, I would say from the limited info here, that it is just normal case expansion.
 
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Norseman79

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In 7 years you've only shot it 250 times???

Without holding it in my hands, I would suggest you have a mild imperfection in the chamber but none I would worry about. Or it's just the way tikka chambers are, much like Glock pistols. I can't see why you wouldn't be able to safely load these unless the "bulge" is more like a mountain peak than a rolling hill.

Thanks for the reply. I'm leaning towards the chamber is just a little generous towards the case head. Which is more than likely normal. I have some brass from a friend that has a mossberg 3006, and his brass also has a slight expansion in the same location. I have noticed that the full length resizing die does seem work that brass a little, so I will just watch the brass and see what happens.


In regards to shooting the rifle only 250 times, recoil in a light 30-06 rifle isn't too bad, by far less recoil less than my 300 win, 458 win mag, or 375 H&H. However, not super fun for long range sessions. The last 3 years I have only shot about 6 rounds per year in this rifle, just to verify zero and foul the bore. I practice shouldering, taking off safety and dry firing at home before hunting season to work muscle memory. Might sound funny, but it does work for smooth trigger pull in the field.

Thanks,

Dan
 
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Norseman79

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The pic does not look bad - normal, actually. Couple of things. Remember that factory ammo is on the small side of specified tolerance, as it has to fit all chambers. Drop a loaded cartridge into the chamber and note that you can wiggle it with your finger. Secondly, the bulge coincides with the transition from case web to the wall of the case. The brass is naturally thinner there, so it fireforms to the chamber. The rest of the case is equally expanded and everything but the head is resized in reloading, as the head does normally expand. Unless this miked out to .020" larger than the head or some excessively large number, I would say from the limited info here, that it is just normal case expansion.

Thanks for your reply. I truly appreciate the response and information. I am also thinking about just neck sizing the brass fired out of my rifle to increase brass life. Anyone do that in a hunting rifle?
 

ma96782

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Looking at the picture...
I wouldn't exactly term that as a "bulged case."

YES, for a bolt gun.....many choose to neck size only. The downside is: usually your reloads (neck sized ones) will generally be GTG with only that gun/rifle.

If you're thinking of reloading for a semi-auto or more than one gun/rifle.....you may just want to fully resize your cases. That way the reloads could be used in any of those instances. The downside is: usually reduced case life.

Aloha, Mark
 
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po18guy

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Thanks for your reply. I truly appreciate the response and information. I am also thinking about just neck sizing the brass fired out of my rifle to increase brass life. Anyone do that in a hunting rifle?
Neck sizing, as mentioned customizes cartridge to individual rifle. With bolt guns it is generally not a huge issue unless you are pushing the pressure envelope. In semi-autos, you are at increased risk of a fail to extract or a fail to go into battery if the neck-sized cartridge is rotated wrong (chambers are not always 100% concentric, or if cartridge or chamber have some grit or unburnt powder kernels on them/in them.

As to brass life, I think there are far more split necks than cases ruined from FL resizing. The upside to neck sizing is accuracy. The downside is mentioned above.

The upside of FL resizing is that you can use the same handloads in any rifle with a SAAMi-spec chamber for that cvratridge. The downside of FL resizing is that the case will grow in length and needs to be trimmed at the case mouth. However, since this is where splitting normally occurs, it is good to check in any event.

Kind of a tossup, but for hunting, unless you are shooting long range and ultimate accuracy is a must, standard FL resizing is fine. It is a little more work, or messier (depending on the case lube), but makes "universal" rounds.

These are the rules I have been taught. There are exceptions, and we shall hear of them. Does not change the rules. Best bet is to load both FL and Neck-sized and head to the range. There, any accuracy or feeding/extraction problems will be noted. At the range, no problem. In the field, well...
 
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Norseman79

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Have a micrometer, or are you just doing visual gauging?
I can show you a bulged case, but I'm too lazy to go find it.

No, just visually. The "expansion ring" as I'm calling it, on the case is high enough that it seems I can feel it with my finger nail. I just measured the difference in the height of the ring and on each side of it, on multiple once fired brass with a caliper, spinning the brass around to get different measurements. Probably not the best method but it's what I have at the moment. It seems to be a little over .001" to .0025" higher on the ring.

Today I read an article from Duane Siercks, from Sierra bullets. He shows the same expansion ring on brass, and his opinion is that it's due to a chamber that's probably on the higher end of sammi specs. Below is a picture of once fired brass and a factory round showing the ring. When I get a chance I'm going to cut some of the brass in half and see what it looks like.

Once again,

Thanks everyone for your input.

dan
3006unfiredvsonce.jpeg
 

po18guy

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An anecdote: .220 Swift cartridges were known to stretch, due to the pressures involved. Back in the 30s through the 50s, some shooters used to pressurize the heck out of them, trying to make them a deer cartridge. Case heads separated, etc. I acquired some older .220 cases decades ago. Seeing the ring right where yours is, I was wondering if it indicated incipient case head separation. So I sectioned two cases with a Dremel and they were just fine.

So, it is a matter of the case wall expanding - a good thing as it locks the case to the chamber and does not allow the cartridge head to hammer the bolt face or locking lugs.

Lube 'em, size 'em and shoot 'em.
 

DLS

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... I am also thinking about just neck sizing the brass fired out of my rifle to increase brass life. Anyone do that in a hunting rifle?
I would not do this in any field gun. First of all brass, especially .30-06, is so cheap that worrying about saving a few pennies in case cost will seem pretty silly when you lose all the money spent on a hunt due to an ammo failure. Since the cost is negligible, I don't go over 3 or 4 reloads in standard hunting cartridges to avoid taking the rifle out of commission due to a case head failure. I limit to 2 or 3 for magnums.

There is really only a couple of reasons to neck size:

One is if the case is rare or hard to make from other existing cases, then gaining case life becomes worth the other risks.

Another is to increase accuracy, but unless you are using a match tuned gun and match grade ammo it's highly doubtful you will see a meaningful difference in your group size.

The last reason I'd neck size is in match type of cartridges / guns. Here case life makes a big difference because of all you do to the case i.e. weight sorting, measuring wall thickness concentricy , uniforming the primer pocket and, flash hole, annealing etc. After doing all of that work you want the case to last, and if you have a head separation during a match you just whip out your broken case extractor tool and pull the offending case from the chamber and get back to shooting. The target hangs around to let you do this … game will not.


As to brass life, I think there are far more split necks than cases ruined from FL resizing.
Agreed!
 

DLS

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Seeing the ring right where yours is, I was wondering if it indicated incipient case head separation. So I sectioned two cases with a Dremel and they were just fine.
If you put a tiny 90-degree bend on the end of a straightened paperclip you can insert it into the case and drag it along the side of the case bottom to top. If an incipient separation is forming you can easily feel it with the clip.

Rabbit Trail: The Swift is a great cartridge to load for and shoot. I love mine!
 

ma96782

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RE: Picture in Post #10

The line may/might indicate possibly impending head separation BUT it's also normal to see that sort of thing in a comparison between.....new case vs. once fired cases. Yup...looks like that.

Do the paper clip test to know.

But....usually with a once fired cases and assuming that the rifle chamber was cut correctly and your headspace is good.....well, it's normal to see that line.

Aloha, Mark
 

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