The extractor groove is much deeper than the Kynoch ammo, the thickness of the rim is much more than the Kynoch, and the shoulder is set back further than the unfired and fired Kynoch ammo. I measured the Jamison against the Kynoch and the CIP specs posted in this thread....neither is spot on, but the Jamison is "out" further. Also, if I place a piece of Kynoch brass or a fully loaded round into the extractor/bolt assembly while it's removed from the rifle, the Kynoch brass remains in place and is held tightly...doing the same with the Jamison brass results in the brass being very loose-fitting to outright falling out of the extractor. The Jamison brass sits off the face of the bolt noticably...and the Kynoch does not.

Is that enough explanation?

Something is not right....and CIP is like being pregnant....it is or it isn't.

The Kynoch ammo fits/feeds and fires thru my new Heym PERFECTLY. But I will not load up any Jamison brass and chance screwing something up...simple as that.

As a side note...the 500 Jeff is the ONLY Jamison brass that I have ever had an issue with.

Gary
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Hi Garby,

Thanks for the explanation. My rifle is under construction presently, so the case dimensions will not be a problem. Is the latest lot of Jamison brass soft like previous ones were?

Andy....brass doesn't appear to be soft...looks to be good quality stuff, just not the same specs as the Kynoch that functions in my Heym.
I sent Mark some once-fired Kynoch brass (from my rifle) for him to compare with his current run. His is going to advise me once he receives it. He is determined to make a the 500 Jeff match the quality of all his other brass...which I find to be very good.

Gary
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Thanks Gary. As long as it'll hold up the dimensions are not as critical to me as they might be to a factory chambered rifle...those cases will just hafta be married to my rifle and not ever sold separately after my retinal detachment occurs.

Andy....might want to re-think as Mark Jamison told me on Tuesday that they have some new tooling from Germany that just arrived and they were re-visiting the 500 Jeff. Heck, the Kynoch stuff may not be the dimensions they end up with...but he assures me it will be CIP....and their brass now isn't.

Gary
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Sorry I didn't get back earlier...Hell yes, it's headspaced correctly! I just received an e-mail from Terri Schroup, engineer at Jameson...she single handedly thoroughly investigated my complaint and she says they are now re-tooling, new gages, etc, have stopped sales of the old 500 Jeff brass and will be issuing new brass with a different headstamp to make the difference obvious

Jameson is fortunate to have her aboard!

Boys...thanks for the suggestion of using the #14 RCBS shellholder for the Kynoch 500 brass Fits like a glove.

Now when I get Jamison's new run of brass, I can go and bruise my shoulder some more.

Gary
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500 Jeffery owners:

Tired of all the brass-incompatibility headaches, misfeeding-related disasters due to rebated rim on a fat cartridge, and catastrophic failures of reworked standard Mausers loaded with data gleaned from this website?

If you are still alive, consider the slicker feeding and plus-one additional capacity of the 500 Mbogo.

The 500 Mbogo may not give the pinky finger of your trigger hand an erection, but it will do anything else the 500 Jeffery can do and much more.

RIP...the mere fact that you would have me consider NOT letting my pinky finger have an erection is utterly unacceptable!

THAT being said, I have an unhealthy and fiscally irresponsible addiction to those classic calibers. I have tried therapy, but to-date, no luck.

I do like the look of that cartridge however....and I know you're tweakin every last bit of zip from it.

What are the ballistics you're loading to?? Bullets, powder, fps, etc.

Thanks.

Gary
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GarBy,
Sir, you are a horny-handed slave to nostalgia.
I do hope you get help soon, or at least a splint for your finger, in flexed position, or at least buddy tape it!

Start with medium 500A2 loads, and work up to exceed the 500 A2 loads.

I will be happy to stop at:
2500 fps for 570-grainers: DG
2750 fps for 450-grainers: Varmints

I am still waiting for Redding to deliver the dies.
I paid for those dies some moons ago, they said they could do it ...
500 Jeffery dies (for neck and crimp) will serve to get me shooting this new brass.

RIP

Did you develope this cartridge?

And is that a brown suit you are wearing?

quote:

Originally posted by maxbear:
RIP

Did you develope this cartridge?

And is that a brown suit you are wearing?

Sir,
Yes, I am the sole individual in the world developing this cartridge at this time. Dave Estergaard approves of the 500 Mbogo. He would have been the first to neck up his 470 Mbogo to .510 caliber about a decade ago. I am the goober that added .055" length to that and called it the 500 Mbogo, or the Fifty of 2008, Fifty-Aught-Eight.

Explain your brown suit comment, please. I'll be watching from the peanut gallery.

Your Goober,
Rip

Hey Rip, popcorn sounds good. Don't worry, I'll get my own.
Well I just thought that since you promote the 500 Mbogo so much that you might have something to do with it's development. I'm sure you are proud of your accomplishment, and good for you. The brown suit...well , that was supposed to be funny. Pimping ain't easy. I meant no harm with my comments. I just don't want this thread to digress from the problem we are having with Jamison's current brass.

RIP.....570 gr @ 2500 fps.....I'll bet that's a gentle caress to the shoulder . My Kynoch factory loads were 535 @ 2300 and that was slightly outside the fun zone from the bench...off the sticks, no worries.
I'm debating....but I may have to stick with nostalgia.....and my taped fingers .

Thanks.

Gary
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I'm gonna stay with the 500 Jeff..nostalgia calls! I spoke with Terry at Jamison this morning and they are retooling for another run of 500 Jeff brass and will exchange it for those who bought from the last lot. Sounds fair to me.

Andy...agreed....can't ask for more than that. I, too, have the disease that RIP references in his post. That being said, for those that want a SERIOUS thumper...at both ends...RIP's new baby sounds very promising. I'm sure it could be loaded down to "nostalgia" velocities, though...right RIP?

Gary
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Garby,
The 470 Mbogo 2.945" is almost identical to the 470 NE 3.25" in case capacity.
You can load the 470 Mbogo full of RL-15 for 2500 to 2700 fps with 500-grainers. That takes about 117 grains of RL-15 to get to 2700 fps.
Or you can load it down with 90 grains of RL-15 and 5 grains of Dacron filler and get 2150 fps with 500-grainers from the 470 Mbogo. Ditto a case full of H4831 for 470NE ballistics in either the 470 Mbogo or 470 NE: about 108 to 110 grains of H4831 with 500-grainer.

The 500 Mbogo 3" is slightly larger in case capacity than a 500 NE 3". Just a trifling difference.

RL-15 or Varget with Dacron filler could duplicate 500 NE ballistics with less recoil than a case full of H4350 or H4831.

I dare say the 500 Mobogo can duplicate any extended pinky finger ballistics desired, from 500 NE right on through 500 Jeffery, and past the 500 A2, across the pressure spectrum.

Thanks for asking.

Highjack off.

I got to shoot lb404's Sterling Davenport 500 Jeffery with some Varget loads, with and without filler, excellent accuracy and good ballistics. Here is the load data for a good load. Leonard was just starting to zero his iron sights so POI and POA had not coincided, but the rifle and load were "shooters."
Load used the "Hornybear" brass:

Nice stuff, RIP...thanks. I am going to try your 105 gr Varget load along side my 110 gr RL15 load (with 535 Woodies)....just waiting on the new Jamison brass.

Gary
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That 50-yard, open-sight 500 Jeffery 3-shot group looks like a 2-shot group.
Leonard (lb404) is my witness. I think the third shot slightly enlarged the lower-right hole of the first two shots.

After seeing that, I wanted to quit the small gold bead for fear of enlarging the hole.
So I flipped up the "moon bead" which was larger in diameter, hence when I used the same, deliberate, fine bead hold, instead of a fast combat hold, it shot lower for the next two shots. Makes sense.

I am plagued by shooting two bullets through the same hole.
It all started when I was a 17 year-old cadet, qualifying as "Expert" with the M-16, the only squirrel hunter in a company of flinching city slickers.

I scored 299/300. The 300th shot went through the same hole at 300 yards.

I just got a call from Triple River Gunsmithing and my .500 Jeffery has been re-barreled and will on it's way home via FedEx this morning. I should have it in a day or two and I will try out some of the brass that was sent to me by Jamsion and let you know if it works.

Dave

Dave....hold off...Jamison has their new stuff almost ready. They are recalling all of the old brass.
RIP.....have you tried any H4895 loads for the 500 Jeff. Looks like the same load of 4895 and Varget give similar velocities with the 4895 having a more complete burn...at 80% case capacity.

Thanks.

Gary
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Thanks Gary.

I'll call them late next week and see what is going on. I have about 100 rounds that I bought from Midway in August of 2007. I am sure that they will exchange it for me for the current run of brass. Jeez, I really like the .500 Jeffery. Up here in cowboy country we use them to hunt jackrabbits from the back of a galloping horse

Dave

Dave, they told me they would exchange the brass for those that bought it. I love the 500 jeff too.....but that galloping horse shooting would scare me a bit...let alone the horse!

Gary
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I bought 100 pcs. directly from Jamison a couple of months ago. Have been meaning to call them for past couple of weeks, but they beat me to the punch! I got a call from Terry at Jamison on Monday afternoon, informing me that the brass I had purchased was out of spec and that I could send it in to be replaced, and Jamison is even picking up the shipping charges! She said the new brass will have two stars on the headstamp to differentiate it from the current brass.

I'm really impressed with that level of customer service, as it seems Jamison really wants to get this situation corrected.

GarBy,
I have not tried H4895 in a 500 Jeffery, but it ought to be great. Same "Extreme" line of powder as Varget, temperature insensitive. Notice the 107 degree F temperature in Oklahoma?

I do think that some Dacron filler compressing the load can only help. If you eliminate all air space and powder shake, you will need less powder for velocity attained, and get even more uniform loads that will not deteriorate over time from bouncing around in the bakkie or on your belt.

I do not own the 500 Jeffery. That was lb404's Sterling Davenport Mauser masterpiece.
I own a 500 Mbogo, and my pinky finger stays flexed when I shoot.

Marc Jamison is a good man and will get everything right. Just having growing pains from all his new startups.