Media in Case vs Pressure

steve4102 · December 17, 2011, 10:19 AM

What if anything would happen if there was a few grains of media left in a 223 case then loaded and fired?

The load in question is a 223 Rem, 65gr Sierra bullet, 25gr H-4895. The powder with this load comes just to the base of the shoulder. In the case with the left over media the powder was almost to the top of the neck.

Could this bullet/powder/media combo cause a catastrophic failure or enough pressure to blow the case apart?

My research tells me that it would be difficult to get enough H-4895 into a 223 case to case a KB let alone a mixture of powder and media, I've been wrong before.

wncchester · December 17, 2011, 10:48 AM

How many grains/kernels of tumbling media are a "few"? That would matter.

Perhaps a better question is why would anyone leave media in a case?

yoter · December 17, 2011, 10:57 AM

From the sound of it, it sounds like more than one or two granuals of media. That could push the pressure up to unsafe levels. I don't have any experience in this matter, but that my two cents.

To be safe, I'd pull them. With things that go boom, its always better to error on the side of safety.

Jim243 · December 17, 2011, 11:11 AM

Quote:

Could this bullet/powder/media combo cause a catastrophic failure or enough pressure to blow the case apart?

Yes.

From what you are saying, you will have a compressed charge (not good). No reason you should have media in your case. Beside, sending media down you barrel, will never improve the life of your rifle.

Jim

mehavey · December 17, 2011, 11:19 AM

Quote:

The load in question is a 223 Rem, 65gr Sierra bullet, 25gr H-4895. The powder with this load comes just to the base of the shoulder. In the case with the left over media the powder was almost to the top of the neck. Could this bullet/powder/media combo cause a catastrophic failure or enough pressure to blow the case apart?.

What you described is "leftover-media-pushes-powder column-from-base-of-shoulder-to-top-of-neck."

If by "top-of-neck" you mean case mouth, that is a LOT of media (not just a few grains). You've affected case volume/pressure at ignition big time if you haven't developed this powder/media load combination from the ground up. Do not shoot.

I've got a bigger question though.

If this is "leftover" media, it's sitting on the bottom of the case/over the flashhole. What makes you think it will even fire?

arch308 · December 17, 2011, 11:26 AM

I always check each flash hole for media before inserting the primers. Seems silly not to.
I can see no reason for leftovers to be in the case other than laziness or carelessness. No offence intended!

mrawesome22 · December 17, 2011, 11:43 AM

Base of shoulder to top of neck is a heck of a lot more than a couple grains of media. The media is packed tightly on the bottom so I would doubt they would fire.

I would certainly pull them all and next time just hold them up and look for light through the flash hole before seating the primer.

swmike · December 17, 2011, 02:03 PM

The problem with the terms "few" and "bunch" is that there is no agreed upon standard for them. If you have enough media left in the case that the powder is raised to the top of the neck then it's clear that you have "too much".

As of a few kernals, meaning only 3 or 4 of them, left in the case I find it interesting when I shoot them. They leave little sparks along the bullet path for a few feet. Not quite like a tracer but noticeable non the least.

603Country · December 17, 2011, 08:44 PM

I've had problems with media blocking flash holes. I caught the problem before I loaded anything with blocked flash holes, but had a devil of a slow time clearing all the holes and any media in the cases. I reload in my woodworking shop and I have a small air compressor in there, so to speed up the process I just used an air nozzle to blow out each case (from the base end). Worked great and really fast.

steve4102 · December 17, 2011, 11:33 PM

OK here's the deal.

A fellow handloader had a catastrophic failure in his Mini-14 a few months ago and he never found the cause. The case looked like this.
http://charlie6.org/c6forum/download/file.php?id=340

A few days ago he was loading for his Mini-14 with the same load and a new powder measure. All powder drops were consistent and they all filled the case to the neck/shoulder junction. All but one, this one case had powder up to the top of the neck. He dumped the powder and charged it a few times and each time the powder was up to the top of the neck. Upon further inspection he found media stuck to the sides of the case. Not packed on the bottom, stuck to the sides.

He concluded that the previous KB was the result of media stuck to the sides of the case.

I don't buy it. In my experiments a full case of H-4895 weighs 27.2gr. Hodgdon lists 26gr as Max with a 69gr bullet. QL calculates 27.2gr with his 65gr Sierra bullet at just under 64K psi. This load will not produce enough pressure to destroy a case like the the picture above.

If a full case full of H-4895 can't produce enough pressure to KB a case, how can a load that is part powder and part media produce this kind of pressure?

Jim243 · December 17, 2011, 11:33 PM

A couple of ideas, if you find that your media is sticking in the cases.

A. Use finer corn cobb or fine walnut or a mix of both 50/50 in my case.
B. The air compressor is a good idea.
C. If no compressor is available, get a set of Dental Picks from Harbor Freight to clean out the cases.
D. When adding brass polisher to your media, run the tumbler for 15 to 20 min before putting any brass into the tumbler.

Jim

mrawesome22 · December 17, 2011, 11:56 PM

Quote:

He concluded that the previous KB was the result of media stuck to the sides of the case.

I don't buy it. In my experiments a full case of H-4895 weighs 27.2gr. Hodgdon lists 26gr as Max with a 69gr bullet. QL calculates 27.2gr with his 65gr Sierra bullet at just under 64K psi. This load will not produce enough pressure to destroy a case like the the picture above.

If a full case full of H-4895 can't produce enough pressure to KB a case, how can a load that is part powder and part media produce this kind of pressure?

Because with the media in the case it reduces internal volume, and that raises pressure.

The case already loaded toward max, then reduce the internal volume, cram a highly compressed charge into it.... I could see a KB being very possible.

EDIT: Jim243 is right on. Add your media additive and let the tumbler run until all the clumps are gone before adding brass.

steve4102 · December 18, 2011, 12:20 AM

Quote:

Because with the media in the case it reduces internal volume, and that raises pressure.

Yes it does, and so does more H-4895, but even more powder isn't enough pressure to KB the case?

mrawesome22 · December 18, 2011, 12:38 AM

With the media in there, it basically is no longer a 223Rem case as the internal volume has been drastically changed.

swmike · December 20, 2011, 12:42 PM

I'm starting to like my Stainless Steel media even more

It not only cleans out the inside of the case but it doesn't clump and stick to the side of the case. No need to run the "tumbler" for up to 15 minutes to make sure the polish is distributed.

SL1 · December 20, 2011, 01:46 PM

to blow media out of a case tumbled in corn cob seems like a good way to put a lot of lead dust in the air, where you can breath it. And, of course, it spreads and settles on everything in the vicinity, too. I would not do that unless I loaded outdoors.

And, I am liking my stainless pin tumbling media, too. Occassionally two pins will get stuck in a flash hole because one is too thin (under spec size). They are obvious and easy to pull out. I throw them away so that they don't do that to me again, and, after a few uses of that media, it stops happening because all the under spec pins are removed. And, those remaining pins never wear out.

SL1

December 17, 2011, 10:19 AM	#1
steve4102 Senior Member Join Date: December 23, 2005 Location: Minnesota Posts: 2,952	Media in Case vs Pressure What if anything would happen if there was a few grains of media left in a 223 case then loaded and fired? The load in question is a 223 Rem, 65gr Sierra bullet, 25gr H-4895. The powder with this load comes just to the base of the shoulder. In the case with the left over media the powder was almost to the top of the neck. Could this bullet/powder/media combo cause a catastrophic failure or enough pressure to blow the case apart? My research tells me that it would be difficult to get enough H-4895 into a 223 case to case a KB let alone a mixture of powder and media, I've been wrong before.

December 17, 2011, 02:03 PM	#8
swmike Senior Member Join Date: June 25, 2005 Location: Marysville, WA Posts: 670	The problem with the terms "few" and "bunch" is that there is no agreed upon standard for them. If you have enough media left in the case that the powder is raised to the top of the neck then it's clear that you have "too much". As of a few kernals, meaning only 3 or 4 of them, left in the case I find it interesting when I shoot them. They leave little sparks along the bullet path for a few feet. Not quite like a tracer but noticeable non the least. __________________ My definition of Gun Control--- A steady grip and hitting your target. "In God we trust, all others are suspects." "If I shoot all the ammo I am carrying, either I won't need any more, or more won't be of any help". ____________________________________________

December 17, 2011, 11:33 PM	#10
steve4102 Senior Member Join Date: December 23, 2005 Location: Minnesota Posts: 2,952	OK here's the deal. A fellow handloader had a catastrophic failure in his Mini-14 a few months ago and he never found the cause. The case looked like this. http://charlie6.org/c6forum/download/file.php?id=340 A few days ago he was loading for his Mini-14 with the same load and a new powder measure. All powder drops were consistent and they all filled the case to the neck/shoulder junction. All but one, this one case had powder up to the top of the neck. He dumped the powder and charged it a few times and each time the powder was up to the top of the neck. Upon further inspection he found media stuck to the sides of the case. Not packed on the bottom, stuck to the sides. He concluded that the previous KB was the result of media stuck to the sides of the case. I don't buy it. In my experiments a full case of H-4895 weighs 27.2gr. Hodgdon lists 26gr as Max with a 69gr bullet. QL calculates 27.2gr with his 65gr Sierra bullet at just under 64K psi. This load will not produce enough pressure to destroy a case like the the picture above. If a full case full of H-4895 can't produce enough pressure to KB a case, how can a load that is part powder and part media produce this kind of pressure? Last edited by steve4102; December 17, 2011 at 11:49 PM.

December 17, 2011, 11:33 PM	#11
Jim243 Senior Member Join Date: January 5, 2009 Location: Just off Route 66 Posts: 5,067	A couple of ideas, if you find that your media is sticking in the cases. A. Use finer corn cobb or fine walnut or a mix of both 50/50 in my case. B. The air compressor is a good idea. C. If no compressor is available, get a set of Dental Picks from Harbor Freight to clean out the cases. D. When adding brass polisher to your media, run the tumbler for 15 to 20 min before putting any brass into the tumbler. Jim __________________ Si vis pacem, para bellum

December 20, 2011, 12:42 PM	#15
swmike Senior Member Join Date: June 25, 2005 Location: Marysville, WA Posts: 670	I'm starting to like my Stainless Steel media even more It not only cleans out the inside of the case but it doesn't clump and stick to the side of the case. No need to run the "tumbler" for up to 15 minutes to make sure the polish is distributed. __________________ My definition of Gun Control--- A steady grip and hitting your target. "In God we trust, all others are suspects." "If I shoot all the ammo I am carrying, either I won't need any more, or more won't be of any help". ____________________________________________

December 17, 2011, 10:48 AM	#2
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	How many grains/kernels of tumbling media are a "few"? That would matter. Perhaps a better question is why would anyone leave media in a case?

December 17, 2011, 10:57 AM	#3
yoter Member Join Date: September 4, 2011 Location: Wisconsin Posts: 28	From the sound of it, it sounds like more than one or two granuals of media. That could push the pressure up to unsafe levels. I don't have any experience in this matter, but that my two cents. To be safe, I'd pull them. With things that go boom, its always better to error on the side of safety.

December 17, 2011, 11:26 AM	#6
arch308 Senior Member Join Date: November 6, 2011 Location: DFW, Texas Posts: 876	I always check each flash hole for media before inserting the primers. Seems silly not to. I can see no reason for leftovers to be in the case other than laziness or carelessness. No offence intended!

December 17, 2011, 11:43 AM	#7
mrawesome22 Senior Member Join Date: November 9, 2005 Location: Ohio, Appalachia's foothills. Posts: 3,779	Base of shoulder to top of neck is a heck of a lot more than a couple grains of media. The media is packed tightly on the bottom so I would doubt they would fire. I would certainly pull them all and next time just hold them up and look for light through the flash hole before seating the primer.

December 17, 2011, 08:44 PM	#9
603Country Senior Member Join Date: January 6, 2011 Location: Thornton, Texas Posts: 3,998	I've had problems with media blocking flash holes. I caught the problem before I loaded anything with blocked flash holes, but had a devil of a slow time clearing all the holes and any media in the cases. I reload in my woodworking shop and I have a small air compressor in there, so to speed up the process I just used an air nozzle to blow out each case (from the base end). Worked great and really fast.

December 18, 2011, 12:38 AM	#14
mrawesome22 Senior Member Join Date: November 9, 2005 Location: Ohio, Appalachia's foothills. Posts: 3,779	With the media in there, it basically is no longer a 223Rem case as the internal volume has been drastically changed.

December 20, 2011, 01:46 PM	#16
SL1 Senior Member Join Date: November 8, 2007 Posts: 2,001	Using an air compressor to blow media out of a case tumbled in corn cob seems like a good way to put a lot of lead dust in the air, where you can breath it. And, of course, it spreads and settles on everything in the vicinity, too. I would not do that unless I loaded outdoors. And, I am liking my stainless pin tumbling media, too. Occassionally two pins will get stuck in a flash hole because one is too thin (under spec size). They are obvious and easy to pull out. I throw them away so that they don't do that to me again, and, after a few uses of that media, it stops happening because all the under spec pins are removed. And, those remaining pins never wear out. SL1