Another board member and I have been discussing simular problem's with 500 Jeffery brass that has been made by Jamison.

We both feel it would be important for the people who own 500 Jeffery rifles to be aware of this serious problem.

I have contacted the custom cartridge manufacture whom I bought my ammunition from who used Jamison brass. He was very understanding of the problem and asked me to send my ammunition back to him so that I could be refunded.

One of the problems lies with the extractor groove depth. It does not follow SAMMI spec's.

We have notified CZ USA of this problem and they have made note. We are waiting to hear back from them with there testing results.

I hope this message makes it to Africa's Professional hunters, and anyone who plans to take there 500 Jeffery to do dangerous buisness.

So what is it and what is it suppose to be?

Will:

I am the other guy Max mentioned and I will try and fill you in as best as I can. I know that there is a problem. However, I am a bit unsure as to how to explain it so let's start at the beginning.

I have what I believe is the first .500 Jeffery made by CZ. When I got the gun, I got 40 rounds of Horneber brass from Huntington's. I have NEVER had a problem with my gun but then again, I have only ever used Horneber brass up until a couple of weeks ago. It feeds, ejects and shoots fine. However, I know that Max had a problem with his gun and I know one other guy who had a problem as well. They were both using Jamison brass. I think maybe Max sent his CZ back, so did the other guy and the other guy had AHR make one up for him with a center feed magazine. AHR loaded up some ammo with Horneber brass, tested the rifle and it worked perfectly. However, when they sent the rifle to him, they sent him some ammo loaded with Jamison brass. It wouldn't eject properly.

Okay, now this is where I come in. I had some Jamison brass on hand that I bought in August of 07 so I told these guys I would load some up and test it in my rifle. I loaded up five rounds with the same load I use in my Hornber brass.... 110 grains of RL15 and a 535 grain Woodleigh soft point. Trust me, this is a very modest load running only about 2260 fps and shows no pressure signs whatever. I was only able to fire one round using the Jamison brass. With great effort, I was able to lift the bolt but I couldn't get the action open at the range. After about 15 minutes, when the gun cooled a bit, I managed to get it open.

Stick with me.... this is a long story.

I called Jamison and talked to "Chris". He told me that they did indeed have a problem with some of their first .500 Jeffery brass. Apparently, the case head was not strong enough. He sent me five rounds of the new brass. I loaded only one this time and when I fired it with the same load, while it didn't stick in the rifle, there were signs of excessive pressure. The was a good deal of stretching ahead of the web and the primer was just flattened.

I conveyed all this information to Jason Morton at CZ and he put me in touch with "Harlan" at the Tripleriver Gunsmithing. They do this work for CZ. Harlan told me that there was a problem with some of the first .500 Jefferys in that their first reamer didn't put in enough free bore resulting in pressure problems with some loads. They have now corrected the problem. I have been instructed to send my gun to them and they will put a new barrel on it free of charge. I am going to get it off to them this week. I have explained to Harlan that I don't think that is the problem with my gun because it shoots the Horneber brass just fine. He suggested that I send it back anyway just to be safe.

At this point, I think that if there is a problem, it is with the Jamison brass. I would strongly caution anyone heading off to a hunt with their .500 Jeffery to be sure and test fire their gun with the Jamison brass. Don't just assume it is okay.

When I get my gun back, I am going to test it again with the second lot of brass that Chris sent to me but I would not hunt with this stuff. I will only hunt with the Horneber brass.

I will let you know how all this plays out.

Dave

Gents, I have a new Heym bolt action 500 Jeff that is due to me any day. I have loaded up about 30 rounds of 500 using Jamison brass purchased from Huntington's about 8 months ago....I think I bought about 100 pieces of this brass. I am going to compare the loaded rounds to the full size snap caps I have and then try someof the rounds once the rifle gets to me. I will let you all know how it goes. Thanks for the heads up.

Gary
DRSS
NRA Lifer
SCI
DSC

Gary:

Measure the extractor groove. On the very first Jamison brass the extractor groove measured .464. The newer stuff measures around .474. The extractor groove on the Horneber brass measures .493.

I will be very anxious to see how this stuff works in your Heym.

Dave

Dave,

I don't see how this has anything to do with the groove in the brass. Maybe the brass is just too soft. If the freebore is too small surely you could see that at the front of the case, maybe?

Hell, drop a hammer on one of the Jamison cases and one of the Horneber cases and see which one is softer!

Hopefully someone will chime in that understands the problem.

Dave...will do. Will....I was wondering myself since I've heard of issues with the CZ 500 Jeff rifles. I'll check it out when my Heym gets here and advise you all. Thanks so much for the heads up....don't want things going wrong on anything like a 500 Jeff!

Gary
DRSS
NRA Lifer
SCI
DSC

quote:

Originally posted by Will:
Dave,

I don't see how this has anything to do with the groove in the brass. Maybe the brass is just too soft. If the freebore is too small surely you could see that at the front of the case, maybe?

Hell, drop a hammer on one of the Jamison cases and one of the Horneber cases and see which one is softer!

Hopefully someone will chime in that understands the problem.

Will, I doubt that the depth of the extraction groove would cause the case to stick in the gun but I bet it could effect how the cartridge ejects. I am already having pressure problems with even modest loads in the Jamison brass. I really don't want to try it again until we figure out what is actually going on here. Maybe it does have something to do with my gun but at this point, I'm betting it's the brass because of how this all played out. We'll see. Anyway, if you are heading out for a hunt, just be sure to test fire this stuff to make sure it is working okay.

Dave

I have had similar problems with Jamison brass, both old and new manufacture, in my 500. I have recently called Huntington's and they are out of Horneber brass with no plans of getting any more any time soon.

I also talked to someone at Black Hills Shooter's Supply about the possibilty of Norma brass, and was told they are expecting to have 500 Jeffery loaded ammo in the "PH" line available in December but haven't heard of any plans to offer componet brass yet.

As far as I know, that only leaves Bertram, which I have been hesitant to try because of what I have read here on AR about Bertram having a tendency to be soft.

There is a definate market, although maybe small, if someone could come to the table with quality amde and readily availible 500 Jeffery brass.

Butch Searcy sent me some loaded Jamison brass and it was softer n butter...It took two reloads and started splitting. I tossed it.

No problems. Schuler chabering.

I am reloading .500 Jeffery for two friends and also had the extractor grove problem (deeper than the CIP maximum) with the Jamison brass. However, there is another problem, at least with the brass I received. The shoulder is further back than the CIP spec, which results in excess headspace. Your sticky extraction may be due to that problem.

If you read all the stuff from the turn of the century there were problems with the old BP cases being too thin and sticking in the chambers.

The brass being too soft seems like the obvious problem.

I would caution anyone NOT to shoot Jamieson brass/ammo. The shoulder is about .030 too far back from CIP specs. If you single load (which is sometimes called for) the extractor will push the round into the chamber sure enough, and if you are lucky, the firing pin may not hit the primer hard enough to set it off....but if it does, a case head seperation will almost certainly occur. If it does not ignite, you now have stuck ammo in the chamber that will have to be pushed out from the muzzle.

The extractor will not grab the case tightly enough because the extracor groove is too deep..If the round will eject, it'll barely fall out the action...the other possibility is that the round may just drop away from the bolt face and at least "get in the way"

The folks at Jamieson would have me believe that the problem is with "American" vs European chambering...this is insulting and stupid ,

I too have used Horoneber brass without any problem whatsoever Bertram....kinda sticky!

quote:

Originally posted by Atkinson:
Butch Searcy sent me some loaded Jamison brass and it was softer n butter...It took two reloads and started splitting. I tossed it.

Ray, Is Jamison brass softer that Bertram? I know you have no love for the Aussie brass either.

quote:

Originally posted by Atkinson:
Butch Searcy sent me some loaded Jamison brass and it was softer n butter...It took two reloads and started splitting. I tossed it.

Allbeit limited, my experience has been just the opposite. This is a piece of Jamison 470 brass that I sectioned after being loaded 8 times, and it's still going.

quote:

Originally posted by Duane Wiebe:
I would caution anyone NOT to shoot Jamieson brass/ammo. The shoulder is about .030 too far back from CIP specs. If you single load (which is sometimes called for) the extractor will push the round into the chamber sure enough, and if you are lucky, the firing pin may not hit the primer hard enough to set it off....but if it does, a case head seperation will almost certainly occur. If it does not ignite, you now have stuck ammo in the chamber that will have to be pushed out from the muzzle.

The extractor will not grab the case tightly enough because the extracor groove is too deep..If the round will eject, it'll barely fall out the action...the other possibility is that the round may just drop away from the bolt face and at least "get in the way"

The folks at Jamieson would have me believe that the problem is with "American" vs European chambering...this is insulting and stupid ,

I too have used Horoneber brass without any problem whatsoever Bertram....kinda sticky!

Good explanation of problems here, which I had not understood regarding the excessively deep extractor grooves on the Jamison "Supposed-500-Jeffery" brass. Wrong headspace too?

This is not the first time Marc has screwed up a first run of brass. He usually admits it and fixes it promptly, but seems to be negligent if he is calling that brass "500 Jeffery."

I hope he has not made more than one run of that.

My .505 Gibbs and 470 Mbogo brass from Jamison has been excellent. Not soft.

He needs to get this "sorted out" if such crap is happening.

I don't believe that the problem is the quality of the brass. Rather, that in the case of the .500 jeffery, they are not adhering to the 2000 CIP specification. Norma's decision to load the 500 Jeffery as a cataloged round may be the best news, if they will adhere to the CIP specification.

CIP maximums do not allow the minus tolerances that Jamison is using according to reports here:

CIP 500 Jeffery: Brass
1) Extractor groove diameter: 0.542", 13.77 mm
2) Base to shoulder: 2.268", 57.48 mm

CIP 12.7x70 (500 Schuler): Brass
1): 0.516", 13.10 mm
2): 2.323", 58.96 mm

If the Jamison brass headspace is short by 0.030" for the 500 Jeffery, then it is 0.085" short for the 500 Schuler. Kaboom.

This brass is neither fish nor foul.

Jamison must be making a new cartridge, the 500 Jamison?

I need some edgeication, I guess!

Do you mean by extractor groove depth as the extractor groove width, from front to back?

I still don't get it as to how this would make brass stick, even if the case shoulder is short.

quote:

Originally posted by Duane Wiebe:
I would caution anyone NOT to shoot Jamieson brass/ammo. The shoulder is about .030 too far back from CIP specs. If you single load (which is sometimes called for) the extractor will push the round into the chamber sure enough, and if you are lucky, the firing pin may not hit the primer hard enough to set it off....but if it does, a case head seperation will almost certainly occur. If it does not ignite, you now have stuck ammo in the chamber that will have to be pushed out from the muzzle.

The extractor will not grab the case tightly enough because the extracor groove is too deep..If the round will eject, it'll barely fall out the action...the other possibility is that the round may just drop away from the bolt face and at least "get in the way"

The folks at Jamieson would have me believe that the problem is with "American" vs European chambering...this is insulting and stupid ,

I too have used Horoneber brass without any problem whatsoever Bertram....kinda sticky!

I think Duane is right about the shoulder being "about .030 too far back". When I shot the newer run of Jamison brass in my gun, there was considerable case stretching just in front of the web. Also evidence of excessive pressure with what I consider a very mild load.

My gun has been sent back to CZ to be re-barreled. I should have it back in two-four weeks. As soon as I bet it back, I'll try the Jamison brass again and let you know how it goes.

Dave

quote:

Originally posted by new_guy:

quote:

Originally posted by Atkinson:
Butch Searcy sent me some loaded Jamison brass and it was softer n butter...It took two reloads and started splitting. I tossed it.

Allbeit limited, my experience has been just the opposite. This is a piece of Jamison 470 brass that I sectioned after being loaded 8 times, and it's still going.

Yea, but that's .470 brass.

I think Jamison will get the .500 Jeffery brass right but we have got to keep working with them and talking about the problems we are having so they can.

Will:

The extractor grove is a seperate problem from the sticky cases. The sticky cases are likely due to problems associated with excess headspace. The overly deep extractor grove means that the extractor claw does not put sufficient pressure on the case, so extraction and ejection are impaired

quote:

Originally posted by loud-n-boomer:
The extractor grove is a seperate problem from the sticky cases. The sticky cases are likely due to problems associated with excess headspace. The overly deep extractor grove means that the extractor claw does not put sufficient pressure on the case, so extraction and ejection are impaired

This is what I had not understood before, but it makes sense.

Dave Bush reported on "The Other Thread" these extractor groove brass diameters:

Horneber: 0.494"
Jamison: 0.464"

Even Horneber is considerably under the CIP maximums for both

500 Jeffery: .542"
500 Schuler: .516"

But Horneber brass works fine?
Jamison brass is 0.030" smaller in extractor groove diameter than the Horneber, but a whopping .078" below the CIP max for 500 Jeffery.

RIP:

Jamison sent me a few rounds of replacement brass to try. If I recall, the extractor groove on the new stuff miked out at .474.

Dave

FWIW,

about 3 years ago I ordered 100pcs of 416 rigby brass from Jamison direct. When I got it most of the brass (90%) was hard to chamber (very stiff bolt close, even after full length sizing) in my factory CZ. Up to this point Norma and A2 brass had worked perfectly. I sent all my brass back to Jamison, they discovered the extractor depth was too shallow, they recut to proper depth and sent the brass back. It has been fine since, I'm coming up on the 2nd reload now with no problems.

quote:

Originally posted by ptaylor:
FWIW,

about 3 years ago I ordered 100pcs of 416 rigby brass from Jamison direct. When I got it most of the brass (90%) was hard to chamber (very stiff bolt close, even after full length sizing) in my factory CZ. Up to this point Norma and A2 brass had worked perfectly. I sent all my brass back to Jamison, they discovered the extractor depth was too shallow, they recut to proper depth and sent the brass back. It has been fine since, I'm coming up on the 2nd reload now with no problems.

So this sounds like the extractor sticking and not the brass, because the extractor is pushed out (radially).

When the gun goes off and the head of the brass expands a tiny bit, it locks or nearly locks the extractor/bolt in the extractor cut.

This would make sense.

Where is the push-feed when you need it?

quote:

Originally posted by ptaylor:
FWIW,

about 3 years ago I ordered 100pcs of 416 rigby brass from Jamison direct. When I got it most of the brass (90%) was hard to chamber (very stiff bolt close, even after full length sizing) in my factory CZ. Up to this point Norma and A2 brass had worked perfectly. I sent all my brass back to Jamison, they discovered the extractor depth was too shallow, they recut to proper depth and sent the brass back. It has been fine since, I'm coming up on the 2nd reload now with no problems.

I recall this. My 470 Mbogo brass got the corrective treatment.

It was easy to fix that brass by turning the extractor groove deeper, brass removal by cutting tool.
It will be tougher to put brass back onto the 500 Jeffery batch.

Maybe Marc had some sort of reaction formation to too thick extractor grooves and over compensated? He'll have PTSD and brass nightmares if he doesn't get a handle on the 500 Jeffery.

quote:

Originally posted by Dave Bush:
RIP:

Jamison sent me a few rounds of replacement brass to try. If I recall, the extractor groove on the new stuff miked out at .474.

Dave

Dave:
That is his idea of corrective action?

The reason I've run out of paience with Jamison is: We had 200 rounds of brass loaded and ready to go, but found the problems in time.

Jamison sugested we pull the bullets and he'd replace the brass...He did so! But with the exact same problems as before...I was as if he just sent us back the old brass

The photo of the sectioned breas is not a 500 Jeff case...so what's the point?

I have used some of the newest run of Jamison 500 Jeffery brass that was completed in late July. I fired 20 or so rounds using the 600 gr. Woodleigh Protected Point over 101.0 to 110.0 grains of RL-15 and had no extraction problems or signs of high pressure at all. The new cases that I have left, to the best of my ability to measure, are 2.263" to the edge of the shoulder. This is on spec. I purchased this brass directly from Jamison. Where did you guys buy your brass? Do retailers still have some of the old and soft brass out there that they are still selling?

quote:

Originally posted by Bitterroot:
I have used some of the newest run of Jamison 500 Jeffery brass that was completed in late July. I fired 20 or so rounds using the 600 gr. Woodleigh Protected Point over 101.0 to 110.0 grains of RL-15 and had no extraction problems or signs of high pressure at all. The new cases that I have left, to the best of my ability to measure, are 2.263" to the edge of the shoulder. This is on spec. I purchased this brass directly from Jamison. Where did you guys buy your brass? Do retailers still have some of the old and soft brass out there that they are still selling?

Yeah...measuring cases is tough...but the juncture of the neck and shoulder should be about 2.422 The juncture of the case body and beginning of the shoulder should be about 2.244. In my case, the replacement brass came direct from Jameson, received Sept 2008

The CIP specs can be downloaded...be sure to look for the revision date of 5-15-02....Any other spec is obsolete

Maybe you can clarify which juncture you're referring to? Just curious...is this a CZ or custom? Do you know the reamers and gages used?

Duane, I have the CIP specs revised 5-15-02. My measurement was to juncture of case body and beginning of shoulder. This rifle was a custom built on a CZ Magnum action. I used reamers and gauges from Elk Ridge and I believe these are made by Dave Kiff.

Here it is, half of that CIP page, dated May 15, 2002: Take note and get it right finally.

I have converted millimeters to inches to save you the arithmetic.

L1 is the base to shoulder length for brass, maximum:
L1 = 2.268"
(It is allowed a -0.20mm tolerance or -0.007874".)

E1 is the extractor groove diameter for brass, maximum:
E1 = 0.5421"
(No tolerance specified, and obviously quite variable according to both Horneber and Jamison.)



Notice the reamer minimum for L1 (2.263") is smaller than the brass maximum L1 (2.268").

An inevitable but small plus-tolerance for the chamber created by the minimum reamer spec fully applied, combined with a minus-tolerance for the brass, will make a nice functional, minimum headspace fit.

Could it be that Jameson purchase their .500 Jeff brass from Bertram's? I had simmelar problem with Bertram cases in my .450 Rigby, even when downloading a 500gr bullet to 2100 ft/ sec it showed difficult primary extraction.

Jamison buying from Bertram is far fetched.

I measured three Bertram 500 Jeffery cases:

extractor groove diameter:
.489"
.488"
.492"
average = 0.490"

caliper and eyeball base to shoulder:
2.271"
2.277"
2.268"
average = 2.272"

The Bertram 500 Jeffery is better than the Jamison dimensionally.

But of course, Bertram is notorious for being soft. Jamison is not soft in my experience.

Rip, I have the same drawing. Notice the rim dia. is .575" and the extractor groove dia. is .542". Something screwy here. That leaves .0165" per side on the rim for the extractor to grip ? My Jamison extractor groove dia. is avg. .455" and my Bertram groove dia. is .470". Both makers rim dia. is.570"

Bitterroot,
Please do not make me think about the 500 Jeffery anymore! I swore off that screwy, rebated, short-necked beast of a cartridge and had a 500 Mbogo built.

The 500 Mbogo Cartridge has a 3" case length with standard .416 Rigby base, COL of 3.750" works fine with common .510 bullets. It is simply a 470 Mbogo necked up and lengthened by 0.055".

Hornady is making the .416 Rigby cylindrical basic now.
Quality cartridge will be headstamping some of that as "500 Mbogo" ... I ordered it and am waiting many moons now to get into the schedule at Quality Cartridge.

Any moon now.

Redding is making the 500 Mbogo reloading dies,
hopefully by Christmas, they cashed my check.

Dave Manson made the 500 Mbogo reamer.

In the spirit of John Rigby, the 500 Mbogo is hereby released to the Gun Trade.

Many moons I have waited ...
Any moon now!
Hoping to wrap up the "Fifty-Aught-Eight" in 2008.

I put a primer in an unfired Jamison case. Single loaded it...As I suspected, the extractor pushed the case forward into the chamber (now too deep, we now have about .030 excess headspace because the Jamison shoulder is simply too far back and way out of 500 Jeff CIP spec)

Pulled the trigger and it went "bang". Even the moderate pressure generated by the primer , pushed the primer out of the pocket and back against the bolt face by.....015". I'm sure the cam on the extractor, being beveled, only pushed the case forward this amount. But what if a full house load of 3031 was in the case?

Common sense says that there would have been a severely stretched case as a minimum, but I'd bet the farm there would have been a case head separation with predictable results. My personal conclusion is that Jamison brass in 500 Jeff is unsafe to fire!.

Realistically, my experiment was pretty easy because my 500 Jeff is a takedown...but I could not push the case out thru the muzzle with the rifle assembled.


I had a bullet in the case and this thing REALLY jammed into the the throat. My customer had furnished the "dummy "and the bullet weighed 1.3 oz. As I write this, damned if I can find a conversion to grains, but I don't think that is too important . The "built in headspace" problem with Jameson brass is the important part.

(1.3 oz) x (437.5 grains/oz) = 568.5 gr

Probably about 570-grain bullets.

Duane, are you sure you headspaced that rifle correctly, or is that batch of Jamison brass dangerous in a properly headspaced 500 Jeffery?