Is This A Sign of Overpressure?


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DaisyCutter
November 9, 2012, 02:53 PM
Below is an image of some of my .44 Mags.


The two cartridges on the left have been fired, resized, and cleaned. The two on the right are brand new.

http://farm8.staticflickr.com/7112/8170174326_7799fef76c_c.jpg


Note the relief area under the rim (see arrows). The image doesn't show it perfectly, but on the used cases, the relief area is expanded/swelled out to roughly the same diameter as the case wall. On the new cases, the relief area is very pronounced.

On the used cases, in some areas, I can't even snag a fingernail when running it under the rim. On the new cases, I can feel the relief area very well.

I know this happens after I fire the brass. From the percentage like this in the reload pile, I know this only happens to one particular loading. I presume it's my hottest load.

My hottest load is 23 grains of Alliant 2400, with a CCI 350 magnum primer, behind a 210 grain Speer jacketed HP. My median cartridge OAL is 1.605", but it can vary between 1.602-1.608".

Per the Alliant website;

http://farm8.staticflickr.com/7277/8170167281_dc1b556832_z.jpg


So Alliant says I'm good to 23.5 grains. However, I'm using mag primers. I'm shooting this in a Ruger Super Blackhawk and Redhawk. The revolvers don't seem to care. They function fine, no binding, no bullets jumping crimp, just a big flash/bang.



Is this a sign of overpressure, or just a normal sign of "used" brass? Is the brass still safe.


FWIW, the headstamp appears normal, no splits, and primers looked good.

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rcmodel
November 9, 2012, 02:59 PM
If they eject normally, it could just be soft brass.

What brand of brass is it??

I would probably continue to use it unless you start having case cracks or seperations.

While planning to buy some Starline brass next time.

rc

Certaindeaf
November 9, 2012, 02:59 PM
Why don't you jam a new one up the diehole and see if that makes them look like that. Can't hurt and might tell you something.

DaisyCutter
November 9, 2012, 03:07 PM
I crammed a couple new ones up the resizing die, and they still have the nice relief area.

FWIW, primer pockets are still tight for the used ones.

The cartridges eject fine after I shoot 'em.


The headstamp is as deep as when new. The brass is Winchester. I got 4 bags of 100 for $16 a bag. It was marked at twice the price, but the store owner told me he'd sell it to me at $16/ea if I agreed to buy all he had (4 bags). He said he wasn't moving any reloading stuff and just wanted the stock gone.

So I've got Winchester brass coming out my ears.

rcmodel
November 9, 2012, 03:23 PM
Well, maybe stop using Mag primers with 2400.

It isn't necessary, or generally recommended.

There have been several cautions through the years from Bryan Pearce in Handloader magazine about unexpected pressure spikes & such with Mag primers & 2400.

rc

cfullgraf
November 9, 2012, 03:24 PM
You do realize the resizing die does not resize all the way to the extractor groove?

Besides the part of the case in the shell holder, there is a little bit of the die that does does not resize the case due to the radius at the mouth of the die.

What you are seeing is just the burnishing from the part of the die that actually does touch the case. If you tumble after resizing, I find the "ring" gets polished out and you do not see it.

Josh45
November 9, 2012, 04:06 PM
I would ditch the magnum primer as 2400 doesn't need it.
Load up about 5 of them without a mag primer and see if it changes.

beatledog7
November 9, 2012, 04:22 PM
Looks like normal expansion to me. Use non-magnum primers with 2400.

I'd load a few about 10% lighter, shoot them, and compare. My bet is they look exactly like the ones that have you concerned. I doubt you'll find much difference in how they shoot either.

DaisyCutter
November 9, 2012, 04:46 PM
I've probably got 60-70 of the magnum primed 2400 hot loads left to shoot.

After that, I'll probably tone my load down a couple grains. The .44 is still a heavy bullet, and I can live with a ~1300 FPS just fine versus the max 1500FPS.

Certaindeaf
November 9, 2012, 05:10 PM
You do realize the resizing die does not resize all the way to the extractor groove?

Besides the part of the case in the shell holder, there is a little bit of the die that does does not resize the case due to the radius at the mouth of the die.

What you are seeing is just the burnishing from the part of the die that actually does touch the case. If you tumble after resizing, I find the "ring" gets polished out and you do not see it.
I hear you. I can't really see the picture/issue that well and thought what the hey.

CraigC
November 9, 2012, 05:30 PM
Pressure signs are meaningless in straight-walled pistol cartridges. Trust your data, verify with a chronograph.

243winxb
November 9, 2012, 05:32 PM
not normal Over pressure. the used cases, the relief area is expanded/swelled out to roughly the same diameter as the case wall. I know this only happens to one particular loading. I can't even snag a fingernail when running it under the rim. I presume it's my hottest load.
http://i338.photobucket.com/albums/n420/joe1944usa/Saved%20stuff-private/44magEdit.jpg

918v
November 9, 2012, 06:06 PM
Normal.

DaisyCutter
November 9, 2012, 09:12 PM
Was hoping for more of a consensus.

For those who state overpressure, can you clarify as a gross overpressure or just minimally overpressure?

ColtPythonElite
November 9, 2012, 09:15 PM
cfullgraf said what I was thinking...looks normal to me.

JLDickmon
November 9, 2012, 09:21 PM
load it til it cracks

918v
November 9, 2012, 09:50 PM
When you fire a full-house load, the base will expand. The base is thicker than the rest of the case wall and will resist sizing more. Hence, it will be shinier after you're done.

beeenbag
November 9, 2012, 09:56 PM
I would ditch the mag primer if it was me...

Why don't you load up a couple, as suggested above, with regular large pistol primers and see what they do? I would do this before shooting what you have left and see if the problem persists. If you still have this with the non magnum primers then you know it is just soft brass. If you don't have it with the non magnums, pull the bullets in what you have loaded.

I really love using 2400 in my .44 magnum. I use 21g. under a 240 xtp for my deer hunting load. 21g. for a 240 is max. I have not seen the issue you have.

243winxb
November 9, 2012, 10:38 PM
Need pressure testing equipment to know for sure. :confused: Brass yields at different pressures depending on its hardness. Your brass is moving & i feel its not normal. To much flow for only one loading. Cartridge Brass-
Material is 70 copper/30 zinc with trace amounts of lead & iron , called C26000. Material starts to yield at 15,000 PSI when soft (annealed), and 63,000 PSI when hard.
Material yields, but continues to get stronger up to 47,000 PSI when soft, and 76,000 PSI when work hardened.

918v
November 9, 2012, 11:32 PM
Your brass is moving & i feel its not normal. To much flow for only one loading

My 357 brass looks just like it after firing 38 Special level loads. It's the sizing die causing this shiny mark. It's normal.

Krogen
November 10, 2012, 12:02 AM
Perhaps I'm missing DaisyCutter's point, but I think he's talking about the groove right above the rim, not the shiny part of the case. If he's saying the groove is expanding out to the surface of the case wall after firing, it would sure get my attention! The case head is solid in that area. If that part is expanding to that amount, something really strange is going on.

Daisy Cutter: Have I understood correctly?

ArchAngelCD
November 10, 2012, 12:07 AM
I don't think it's overpressure for more than 1 reason. First, you said the cases fall right out without binding. Second, I would think the case would swell well before the base of the case which is much more stiff.

BUT, I would stop using a magnum primer after you get through shooting the cases that are already loaded. As said above, 2400 does not need a magnum primer and magnum primers are reported to cause pressure spikes when used with 2400. I would not however drop the charge weights unless you see excessively high velocities when the ammo is shot over a chrono. (IMHO or course)

DaisyCutter
November 10, 2012, 08:27 AM
Perhaps I'm missing DaisyCutter's point, but I think he's talking about the groove right above the rim, not the shiny part of the case. If he's saying the groove is expanding out to the surface of the case wall after firing, it would sure get my attention! The case head is solid in that area. If that part is expanding to that amount, something really strange is going on.

Daisy Cutter: Have I understood correctly?

Exactly, it's the groove under the rim. The new cartridges have a pronounced groove. The used ones have little/no groove. It's not optical, I can feel it.

armarsh
November 10, 2012, 09:46 AM
From the 5-6 manuals I looked at you are at or over max. Here is what quickload has to say:

http://i609.photobucket.com/albums/tt174/armarsh/44mag210grjhc23grn2400.png


It is strange you are not having extraction issues or loose primers if the load is causing the head to expand though. Maybe the relief cut is not really below brass level and you are feeling a burr which gets ironed out with this fairly warm :) load. Until primers start to loosen I don't think you are in trouble.

Another thing to think about is that Gold Dots are plated bullets. Other jacketed bullets would probably be something to consider with your full-on loads.

beatledog7
November 10, 2012, 10:14 AM
Now I'm really wondering, how can a case suffer that kind of expansion in the extractor groove and not show any typical sign of overpressure?

Krogen
November 10, 2012, 11:39 AM
'zactly! :-)

The case head is solid there. Sizing dies don't reach that area, so he's probably not "smushing" the case.

Ken Waters used to (try) to judge rifle pressures by measuring case head expansion with a micrometer. In the following years, that method hasn't been well-accepted. Even so, Ken was looking for expansions of around 0.001" at rifle pressures. If DaisyCutter is truly seeing fingernail-detectable expansions in that area of a handgun case, something's definitely amiss; especially when it's not accompanied by sticky extraction or other issues.

Never heard of this one before. DaisyCutter: Can you get some clear close-up photos of this area - before and after? It would be especially helpful to see the same particular case when new, just-fired and then re-sized.

918v
November 10, 2012, 12:49 PM
If the groove is disappearing, then you are correct, the pressure is excessive. Are you experiencing sticky cases? Cases get sticky at about 45000 PSI in a N-frame 357, prolly a lot less in a 44 due to thinner cylinder walls.

CraigC
November 10, 2012, 01:07 PM
If a Super Blackhawk is in danger at 40,000psi, then we're all in trouble. All you guys are doing is trying to justify the myth that pressure signs hold any meaning in straight-walled revolver cartridges. They do not.


Another thing to think about is that Gold Dots are plated bullets.
Gold Dots are NOT the same as plated bullets like Raniers. They sure as hell won't cause any issues at handgun speeds.

Steve C
November 10, 2012, 02:40 PM
Mag primers will increase pressure with 2400 over standard primers. Note that the Speer data used standard CCI 300 primers. In my experience I have seen obvious pressure signs (pierced and cratered primers) in the .357 mag using 2400 with CCI mag primers and loads that where 5% below maximum. For 2400 I stick with standard primers or close to 10% reduced start level loads.

DaisyCutter
November 10, 2012, 02:46 PM
I'll get some better pics tonight.

KevinR
November 10, 2012, 03:14 PM
I see the same thing all the time. I tend to look at the primer for all of my pressure indications. Holes burned through the primer, flat primers and so on.

gamestalker
November 11, 2012, 01:21 AM
There ain't nothing wrong with that brass. But as already stated, stop using magnum primers with powders that dn't require it. If you were using H110 or 296 then a mag primer is needed to light that stuff up, but not for 2400.

Using those powder charges you'll probably get 20-30 reloads from your brass. I use H110 and I still mamange to get about 20 cycles before I have to toss them out.

GS

armarsh
November 11, 2012, 10:50 AM
DaisyCutter - As it turns out, I have some unfired Winchester 44 mag brass. I took a close look at it and I noticed the relief cut is not concentric. It is deeper on one side than the other. Is that what you are seeing? If so, that is just the way it is made.

armarsh
November 11, 2012, 11:18 AM
...Gold Dots are NOT the same as plated bullets like Raniers. They sure as hell won't cause any issues at handgun speeds.

You might want to let Speer know that. Just so it is clear, my recommendation to find another bullet for full power loads has nothing to do with the trouble(?) the OP has with the cases.

http://www.speer-bullets.com/pdf/ReloadingSupplementalDATA/44_200GD.pdf

Note the part where Speer says that 44 cal Gold Dots were "Designed from the start as a low to medium velocity projectile..."

CraigC
November 11, 2012, 11:34 AM
You might want to recheck yourself. That's the sheet for the 200gr Gold Dot designed for the .44Spl, smart guy. If you were paying attention, you'd see that Speer #14 has data for the 210gr GDHP, the bullet in question, at up to 1600fps. I drive the 240gr Gold Dot near 2000fps out of rifles.

DaisyCutter
November 11, 2012, 05:16 PM
Here are some higher quality pics:


As before, the 2 left are fired, resized, and tumbled... the 2 right are new.

All are Winchester.

http://farm9.staticflickr.com/8062/8176691284_cd87b40611_c.jpg




Below is a close-up of a brand new example, note the groove under the rim.

http://farm9.staticflickr.com/8067/8176685244_9e644a16ce_c.jpg



Below is a representative fired, resized, and tumbled case. Note, not much left of the groove.

http://farm9.staticflickr.com/8347/8176654013_94ce6e9daf_c.jpg



Here's a comparison of the heads, Used left and new right.

http://farm9.staticflickr.com/8342/8176684498_2be1bdd81c_c.jpg



Going forward, I'll be reducing my charge or switching from the mag primers. Currently I have 400-500 mag primers to use up.

Would you shoot the remaining 60-70 hot loads remaining if you were me? Versus throwing them away? Would you reuse the brass?

918v
November 11, 2012, 06:52 PM
Disassemble them.

Krogen
November 11, 2012, 07:40 PM
Excellent photos, DaisyCutter. Sure shows what you've been describing. Clearly the metal in the groove is moving outward. And clearly, the case wasn't sized excessively as seen by the reduction in exposed rim. The diameter of the rim compared to the case body remained the same. The groove didn't! It's almost as if those are the old folded head design. But I'm sure they were long gone by the time the 44 Mag arrived. Could the brass be dead-soft in the head area? As in faulty annealing by the factory?

I'll say I'm stumped. As 918v suggests, section one and see what's going on inside.

bds
November 11, 2012, 07:47 PM
As 918v suggests, section one and see what's going on inside.
When I saw the detail pictures, I went WOW! :eek:

+1 on sectioning the case and can you post the pictures of before and after? Also, can you section other fired headstamp cases as comparison?

Curious what the sectioned pictures show ... Thanks!

Cosmoline
November 11, 2012, 07:49 PM
Something is sure going on there. Are the primers all cratered? Are the primer holes expanding?

cfullgraf
November 11, 2012, 08:41 PM
DaisyCutter,

If you have any loaded rounds left, have you looked at the groove in them?

Did you look at the groove before running the fired cases into the resizing die?

Maybe they were manufactured that way.

Did they fit easily in the shell holder when you loaded them? Do they still easily fit in the shell holder?

ArchAngelCD
November 11, 2012, 10:25 PM
After looking at those better pictures I changed my mind, there is something going on there alright. You might want to send a copy of those pictures to Winchester and ask them.

CraigC
November 12, 2012, 12:15 AM
Have you chronographed these loads? If the velocity is not out of line, you've probably got some overly soft cases. A charge of 23.0gr 2400 shouldn't cause any problems with bullets in that weight range but you really should switch to standard primers.

DaisyCutter
November 12, 2012, 03:41 AM
Chrony is on the short list, so I'll probably get one before I shoot any more from this recipe.

BTW, could this be a function of too tight a crimp?

I'll adress the other questions once I get some sleep.

SlamFire1
November 12, 2012, 07:13 AM
How come you are not blowing primers?

I don't like the look of your case heads. You are producing enough pressure to reform the exterior of your case heads. I agree Blackhawks are very strong and all that, but cases are not. It would be interesting to see a sectioned case and see if the inside of the case head has been thinned or the shape changed by the flattening of the extractor groove. Either one would be bad.

I think your loads are too hot for the brass you are using and you should drop the magnum primer and cut your loads.

This is what overpressure does to 45ACP cases that are not well supported by the chamber. Brass will flow at high enough pressures.

http://img.photobucket.com/albums/v479/SlamFire/Reloading/Buldged45ACPcase2.jpg

SSN Vet
November 12, 2012, 11:42 AM
post deleted

meant to start a new thread

floydster
November 12, 2012, 02:35 PM
Wow!! I shoot a lot of 44Mag using 2400, Unique and 4227--never seen anything like this before, however I don't use mag primers, will be interesting to find out the cause.

floydster
November 12, 2012, 08:18 PM
Well, I checked several hundred of my 44 mag cases including Win, none have the groove expanded as in your photos, and I run some pretty hot loads using 2400.
Seems to me it would almost be impossible for that to happen that far down on the case---just sayin.

Walkalong
November 12, 2012, 08:58 PM
After looking at those better pictures............. there is something going on there alright. Yep. As posted, have you checked the velocities you are getting? That is either soft brass or high pressure. If it is soft in the case head area it could be dangerous.

NCsmitty
November 12, 2012, 10:35 PM
My guess is high pressure but not excessive, otherwise the primer pockets would start to loosen. Could be an issue with the brass and the clearance cut making the brass too thin in a critical area. Get rid of the magnum primers and/or drop the charge a bit.


NCsmitty

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