357 mag case head separation ?

Metal god · April 4, 2019, 02:04 PM

Although I did not think this to be impossible , I am a little surprised I ran into this on a 500ct of brass I picked up from the gunshow .

That is unsized and failed the paper clip test , I plan to cut it open later today . So far I've had 4 out of the 500 like this . Not bad but others seem a bit stretched out but pass the paper clip test . Also had what felt like some pretty loose primers when depriming the cases . Hope the primer pockets aren't all blown out .

NoSecondBest · April 4, 2019, 03:16 PM

In fifty years of shooting the .357, I've never seen anything like that. I wonder what kind of gun it was shot out of. I seriously doubt it was a revolver unless someone "Bubba'd" the cylinder for some reason. Maybe a rifle where someone reamed it for some reason and didn't know what they were doing?

Nick_C_S · April 4, 2019, 04:47 PM

Obviously, pressure is the ultimate culprit; however, I suspect a loose chamber attended the party.

Metal god · April 4, 2019, 05:22 PM

Yep , was thinking lever gun with generous chamber or semi unsupported like a clock . My buddy has a custom lever gun that bloats factory loads . He sent it back and they said it was in spec and that they cut the lower back section of the chamber fatter to help feeding .

buck460XVR · April 4, 2019, 06:48 PM

Quote:

Originally Posted by Metal god

Yep , was thinking lever gun with generous chamber or semi unsupported like a clock . My buddy has a custom lever gun that bloats factory loads . He sent it back and they said it was in spec and that they cut the lower back section of the chamber fatter to help feeding .

Could very well be from a lever. I generally only run full power loads thru brass used in levers twice, because of how .357 levers stretch brass. What kind of brass was it? Were all 4 that showed separation the same kind?

Sequins · April 4, 2019, 06:51 PM

I didn't realize levers trashed brass like that, wow. I can't imagine brass like that coming out of any of my wheels...

NoSecondBest · April 4, 2019, 08:45 PM

Quote:

I didn't realize levers trashed brass like that, wow. I can't imagine brass like that coming out of any of my wheels...

In general, they don't. I've owned a couple and I know a lot of guys who own .357 lever guns. I've never seen it before. It appears a lever can do this, but it has to be pretty unusual.

tangolima · April 5, 2019, 01:13 AM

Excessive headspace + hot load. Same mechanism anywhere. Haven't seem one myself. Will probably never will as I don't do hot enough loads in pistol caliber, but won't be surprised to see it in other people's brass.

-TL

PS. I think I have seen one among M1 carbine once fired brass I bought. M1 carbine is almost same as 357 magnum.

Sent from my SM-G930T using Tapatalk

**44 AMP** · April 5, 2019, 01:36 AM

Quote:

M1 carbine is almost same as 357 magnum.

I guess that depends on your definition of "almost the same". The only thing the .30 carbine and .357 have in common is the same case LENGTH.

Other wise, I don't see much in common as the .357 is a rimmed straight wall case and the carbine is rimless, tapered, and smaller at the case head than the .357 is at the case mouth.

I hope that gun show brass wasn't advertised as "once fired", it doesn't seem to be just once fired.

head separation can happen with anything. It's less common with straight cases, but it can happen.

Metal god · April 5, 2019, 01:48 AM

Quote:

What kind of brass was it? Were all 4 that showed separation the same kind?

All the brass is Federal .

Quote:

I hope that gun show brass wasn't advertised as "once fired", it doesn't seem to be just once fired.

No it wasn't , he's pretty good about that . He claims most is in good shape but he can't spot all the bad ones . I've done a fare amount of business with this guy over the years and I'm pretty happy with what I get . He travels with the gun show through out the south west . I call him up a few weeks before the show is supposed to be in San Diego and place my order to be sure he will have what I need .

Sorry guys I've not got to cutting it open , when I do I'll post the photos .

tangolima · April 5, 2019, 01:51 AM

Pressure. .357: 35k psi, .30 carbine: 38k psi.

Both are straight wall (non-bottle-necked).

They are quite similar in many regards.

-TL

Sent from my SM-G930T using Tapatalk

F. Guffey · April 5, 2019, 09:53 AM

As I have said before component manufacturers do not make cases for reloaders that know what they are doing. About the time the reloaders believes he understands clearance and head space they have to start over with a case that has a rim.

If component manufacturers made rimmed cases for me they would make cases with rims of difference thickness: I am the fan of cutting down on all that case travel.

F. Guffey

mikld · April 5, 2019, 10:09 AM

Just thinkin'; separation comes from stretching (for whatever reason; pressure, chamber, etc.). So in the case of a straight case wouldn't the front/mouth of the case need to be held while the head moved rearward? Can't visualize that happening in a revolver...

F. Guffey · April 5, 2019, 11:01 AM

Quote:

Just thinkin'; separation comes from stretching (for whatever reason; pressure, chamber, etc.). So in the case of a straight case wouldn't the front/mouth of the case need to be held while the head moved rearward? Can't visualize that happening in a revolver...

I understand: I am surrounded by people with visualizing problems. The rim prevent the case from being driven into the chamber, that puts the clearance behind the case head. And then

there is the hammer with the firing pin. when the hammer falls the round is fired and then we follow the sequence of events. The case locks to the chamber, when the case lock to the chamber the rear of the case is driven back. With the case locked to the chamber and the rear of the case moving back the case stretches.

Slow motion: When watching a revolver being fired watch the hammer, it bounces. Now I ask; is the bounce of the hammer caused by the dent in the primer being removed or the case head moving back?

And we know if the case head does not move back the primer will protrude.

F. Guffey

But if I had rimmed cases with thicker rims I could reduce some of the case travel.

NoSecondBest · April 5, 2019, 11:53 AM

Guffy, sounds good on paper. Now, who's ever seen this much head space in a revolver? No way! The chamber/cylinder was "bubba'd" to get that effect. Someone removed metal to allow that much expansion at the base area of the case. Really, look how long that area is. That's not headspace in a revolver.

zeke · April 5, 2019, 12:28 PM

If memory holds, there are/were several brands of semi-auto pistols in 357 mag. Have no clue what their actions may do to brass. During a previous discussion on trimming pistol brass, indicated full bore 44 mag rounds out of lever stretched the brass, and kept them separate from the revolver brass due to inconsistent case length affected the crimp.

Have never seen 357 brass stretched like that, but will never be able to see it all.

NoSecondBest · April 5, 2019, 02:08 PM

Just a thought here, but I had two original Dan Coonan semi autos for .357mag. Never had a problem with them, but is it possible that someone had one and it was firing out of battery? That's about the only thing I can think of with that much case stretch other than a corrupted chamber.

totaldla · April 5, 2019, 02:32 PM

I'm wondering what a guy could've done to stretch the frame on a 357 Mag levergun enough to produce that.

jaguarxk120 · April 5, 2019, 02:43 PM

I was thinking a semi-auto with a worn out recoil spring.
It would allow the gun to come out of battery before pressure's dropped enough
for the brass to relax from gripping the chamber walls.

F. Guffey · April 5, 2019, 04:14 PM

Alex Hawkins said "This is my story and I am sticking with it".

I do not have fewer than 8,000 38 Special cases and I am a little light on 357 Magnum cases. Out of all those cases I do not have one that has a line around the case above the cup. I do not have a die that could cause the line. But if I had a line around the case that was caused by the case head clearance and we all know the hammer drives the case forward and then there is the powerful primer exploading and some of us understand if the primer protrudes after firing the case was a little light on the powder; I like it when the cases slams back and reseats the primer.

F. Guffey

F. Guffey · April 5, 2019, 04:19 PM

And then there is crimping; I am the fan of getting all the crimp I can get. Picture this

, a reloader managed to get an incredible amount of crimp. The big time crimp could have refused to let the bullet go and in the process the bullet leaving could have pulled the front of the case while the rim did what it was supposed to do.

F. Guffey

Metal god · April 5, 2019, 04:31 PM

I personally don’t think it’s an out of battery issue . My thinking is fired in a generous chamber . This is causing the case to expand to much or more then normal . Then sized down . Repeat this multiple times and maybe you thin the web wall out . What that number of reloads might be to cause this is hard to say . .

totaldla · April 5, 2019, 05:18 PM

Pretty sure this is from a lever gun cause I've seen this happen with a 30-30 that had been stretched from "Paco Kelly" loads (I think that guy helped folks ruin Marlin 336s).

Basically the bolt is sitting back from the rim a bit too much (headspace). Pressure causes the case to stick to the chamber walls and the pressure is plenty high enough to stretch the brass backwards to the bolt face. When you stretch it past the elastic point you get a thin spot just before the much thicker case head.

I guess I always assumed that nobody would be hot-rodding the little 357 Mag levergun to the point where the frame stretched - just not something I've ever seen.

If a semi-auto was out of battery you would get bulged brass (glock guppy).

gwpercle · April 5, 2019, 07:04 PM

Some times those "once fired" gun show magnum brass bargains turn out not to be such a good deal.
357 magnum brass tend to loosen primer pockets and have head separations faster than lower pressure brass...like 38 special and 45 acp. After getting burned on some "magnum brass deals " I've found the better deal is buy 200 brand new starline and keep a close record of what was loaded in them. 357 magnum last a lot longer when loaded just below the maximum allowed and when starting out with quality cases.

I was reloading an assortment of 357 range pickups , primers kept falling out of pockets and realized Star line brass wasn't that expensive and the unknown history of the fired stuff I had was in reality a problem.

Keep the once fired for mid range and target loads.... for heavy magnum buy some new brass and keep a record of the number of times reloaded.
Gary

Rifletom · April 5, 2019, 07:44 PM

Interesting stuff here. I just measured 25 .357 cases fired thru my lever rifle.
Five went 1.285". The rest are 1.280". Right where they're supposed to be. I wouldn't have thought they'd stretch at all, but, there it is. Only .005, but still.
These are not hot loads: 10.0gr 2400, 158gr RNFP plated in Fed cases. OAL is 1.570".

April 4, 2019, 02:04 PM	#1
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,876	357 mag case head separation ? Although I did not think this to be impossible , I am a little surprised I ran into this on a 500ct of brass I picked up from the gunshow . That is unsized and failed the paper clip test , I plan to cut it open later today . So far I've had 4 out of the 500 like this . Not bad but others seem a bit stretched out but pass the paper clip test . Also had what felt like some pretty loose primers when depriming the cases . Hope the primer pockets aren't all blown out . __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again . Last edited by Metal god; April 4, 2019 at 08:51 PM.

April 4, 2019, 04:47 PM	#3
Nick_C_S Senior Member Join Date: March 21, 2013 Location: Idaho Posts: 5,523	Obviously, pressure is the ultimate culprit; however, I suspect a loose chamber attended the party. __________________ Gun control laws benefit only criminals and politicians - but then, I repeat myself. Life Member, National Rifle Association

April 4, 2019, 05:22 PM	#4
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,876	Yep , was thinking lever gun with generous chamber or semi unsupported like a clock . My buddy has a custom lever gun that bloats factory loads . He sent it back and they said it was in spec and that they cut the lower back section of the chamber fatter to help feeding . __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again .

April 5, 2019, 10:09 AM	#13
mikld Senior Member Join Date: February 7, 2009 Location: Southern Oregon! Posts: 2,891	Just thinkin'; separation comes from stretching (for whatever reason; pressure, chamber, etc.). So in the case of a straight case wouldn't the front/mouth of the case need to be held while the head moved rearward? Can't visualize that happening in a revolver... __________________ My Anchor is holding fast! I've learned how to stand on my own two knees...

April 5, 2019, 02:32 PM	#18
totaldla Senior Member Join Date: August 10, 2009 Location: SW Idaho Posts: 1,295	I'm wondering what a guy could've done to stretch the frame on a 357 Mag levergun enough to produce that. __________________ Lee Auto Bench Prime Castor Oil Case Lube

April 4, 2019, 03:16 PM	#2
NoSecondBest Senior Member Join Date: December 7, 2009 Location: Western New York Posts: 2,736	In fifty years of shooting the .357, I've never seen anything like that. I wonder what kind of gun it was shot out of. I seriously doubt it was a revolver unless someone "Bubba'd" the cylinder for some reason. Maybe a rifle where someone reamed it for some reason and didn't know what they were doing?

April 4, 2019, 06:51 PM	#6
Sequins Senior Member Join Date: October 14, 2014 Posts: 394	I didn't realize levers trashed brass like that, wow. I can't imagine brass like that coming out of any of my wheels...

April 5, 2019, 01:13 AM	#8
tangolima Senior Member Join Date: September 28, 2013 Posts: 3,827	Excessive headspace + hot load. Same mechanism anywhere. Haven't seem one myself. Will probably never will as I don't do hot enough loads in pistol caliber, but won't be surprised to see it in other people's brass. -TL PS. I think I have seen one among M1 carbine once fired brass I bought. M1 carbine is almost same as 357 magnum. Sent from my SM-G930T using Tapatalk

April 5, 2019, 01:51 AM	#11
tangolima Senior Member Join Date: September 28, 2013 Posts: 3,827	Pressure. .357: 35k psi, .30 carbine: 38k psi. Both are straight wall (non-bottle-necked). They are quite similar in many regards. -TL Sent from my SM-G930T using Tapatalk

April 5, 2019, 09:53 AM	#12
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	As I have said before component manufacturers do not make cases for reloaders that know what they are doing. About the time the reloaders believes he understands clearance and head space they have to start over with a case that has a rim. If component manufacturers made rimmed cases for me they would make cases with rims of difference thickness: I am the fan of cutting down on all that case travel. F. Guffey

April 5, 2019, 11:53 AM	#15
NoSecondBest Senior Member Join Date: December 7, 2009 Location: Western New York Posts: 2,736	Guffy, sounds good on paper. Now, who's ever seen this much head space in a revolver? No way! The chamber/cylinder was "bubba'd" to get that effect. Someone removed metal to allow that much expansion at the base area of the case. Really, look how long that area is. That's not headspace in a revolver.

April 5, 2019, 12:28 PM	#16
zeke Senior Member Join Date: November 17, 1999 Location: NW Wi Posts: 1,671	If memory holds, there are/were several brands of semi-auto pistols in 357 mag. Have no clue what their actions may do to brass. During a previous discussion on trimming pistol brass, indicated full bore 44 mag rounds out of lever stretched the brass, and kept them separate from the revolver brass due to inconsistent case length affected the crimp. Have never seen 357 brass stretched like that, but will never be able to see it all.

April 5, 2019, 02:08 PM	#17
NoSecondBest Senior Member Join Date: December 7, 2009 Location: Western New York Posts: 2,736	Just a thought here, but I had two original Dan Coonan semi autos for .357mag. Never had a problem with them, but is it possible that someone had one and it was firing out of battery? That's about the only thing I can think of with that much case stretch other than a corrupted chamber.

April 5, 2019, 02:43 PM	#19
jaguarxk120 Senior Member Join Date: February 28, 2008 Location: Michigan Posts: 2,620	I was thinking a semi-auto with a worn out recoil spring. It would allow the gun to come out of battery before pressure's dropped enough for the brass to relax from gripping the chamber walls.

April 5, 2019, 04:14 PM	#20
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	Alex Hawkins said "This is my story and I am sticking with it". I do not have fewer than 8,000 38 Special cases and I am a little light on 357 Magnum cases. Out of all those cases I do not have one that has a line around the case above the cup. I do not have a die that could cause the line. But if I had a line around the case that was caused by the case head clearance and we all know the hammer drives the case forward and then there is the powerful primer exploading and some of us understand if the primer protrudes after firing the case was a little light on the powder; I like it when the cases slams back and reseats the primer. F. Guffey Last edited by F. Guffey; April 5, 2019 at 04:15 PM. Reason: change r to t

April 5, 2019, 04:19 PM	#21
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	And then there is crimping; I am the fan of getting all the crimp I can get. Picture this, a reloader managed to get an incredible amount of crimp. The big time crimp could have refused to let the bullet go and in the process the bullet leaving could have pulled the front of the case while the rim did what it was supposed to do. F. Guffey

April 5, 2019, 04:31 PM	#22
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,876	I personally don’t think it’s an out of battery issue . My thinking is fired in a generous chamber . This is causing the case to expand to much or more then normal . Then sized down . Repeat this multiple times and maybe you thin the web wall out . What that number of reloads might be to cause this is hard to say . . __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again .

April 5, 2019, 05:18 PM	#23
totaldla Senior Member Join Date: August 10, 2009 Location: SW Idaho Posts: 1,295	Pretty sure this is from a lever gun cause I've seen this happen with a 30-30 that had been stretched from "Paco Kelly" loads (I think that guy helped folks ruin Marlin 336s). Basically the bolt is sitting back from the rim a bit too much (headspace). Pressure causes the case to stick to the chamber walls and the pressure is plenty high enough to stretch the brass backwards to the bolt face. When you stretch it past the elastic point you get a thin spot just before the much thicker case head. I guess I always assumed that nobody would be hot-rodding the little 357 Mag levergun to the point where the frame stretched - just not something I've ever seen. If a semi-auto was out of battery you would get bulged brass (glock guppy). __________________ Lee Auto Bench Prime Castor Oil Case Lube

April 5, 2019, 07:04 PM	#24
gwpercle Senior Member Join Date: November 30, 2012 Location: Baton Rouge, Louisiana Posts: 1,752	Some times those "once fired" gun show magnum brass bargains turn out not to be such a good deal. 357 magnum brass tend to loosen primer pockets and have head separations faster than lower pressure brass...like 38 special and 45 acp. After getting burned on some "magnum brass deals " I've found the better deal is buy 200 brand new starline and keep a close record of what was loaded in them. 357 magnum last a lot longer when loaded just below the maximum allowed and when starting out with quality cases. I was reloading an assortment of 357 range pickups , primers kept falling out of pockets and realized Star line brass wasn't that expensive and the unknown history of the fired stuff I had was in reality a problem. Keep the once fired for mid range and target loads.... for heavy magnum buy some new brass and keep a record of the number of times reloaded. Gary

April 5, 2019, 07:44 PM	#25
Rifletom Senior Member Join Date: February 11, 2011 Location: So-Cal Posts: 789	Interesting stuff here. I just measured 25 .357 cases fired thru my lever rifle. Five went 1.285". The rest are 1.280". Right where they're supposed to be. I wouldn't have thought they'd stretch at all, but, there it is. Only .005, but still. These are not hot loads: 10.0gr 2400, 158gr RNFP plated in Fed cases. OAL is 1.570".