Having owned my 500 Jeffery for about five years I have a question that has been nagging at me. My go to load for the 500 Jeffery has been a Barnes 570g TSX or Banded Solid, 103g H4895 with Federal 215 primers for about 2300 fps. It's very accurate, recoil is fine offhand, no issues. My experience is that 105g giving over 2400 fps is not only a tad unpleasant but one day at 90 plus degrees with the ammo being left out in the sun gave me slightly sticky extraction.

My question is this, in the book "Any Shot You Want" it lists the max pressure for the 500 Jeffery at 40,000 but the 500 A2 at 63,000. Is the Jeffery max pressure based on older rifles, or a weakness in the case design, or something else? If it's simply older rifles I could get more velocity safely by going to IMR 4350, not that I need it.

Just wondering ...


Thanks!

The loads in my 505 Gibbs are kept to it's traditional low pressures, even though the action is a modern Mauser 98.
My 505 Gibbs cases are '408 Cheytac-based' ie can be modified from this high-pressure case.
So it's not action strength nor case strength, in my situation.
Rather, it's because more power is not really needed
Peter

http://www.huntnetwork.net/mod...0The.505%20Gibbs.pdf
http://www.huntnetwork.net/mod...n/html/505magnum.pdf

Hi Chuck

Look at the book again. The 500 Jeffery is listed as CUP's and the 500 Asquare is listed as PSI. Two different measurements.

Mark

Thanks Mark. I know the CZ 550 action is strong and I really don't need any more velocity. Thanks for the correction. It's amazing how much the subjective recoil changed when I pushed that 570g TSX up from 2300 fps to 2410 fps. I must have just reached my recoil tolerance.

Chuck

My 460 wby is the same way. I can run a 500gr bullet up to 2750fps but I choose to shoot it at 2650fps as the felt recoil is much more. It is the same when I shoot the 600gr at 2300fps as compared to 2400fps. The 585 Nyati I had was the same way. Shoot the 750gr at 2200fps and it would rattle my teeth but controlable! But at 2400fps it was just way to much for me. I would experience dull neck and head aches after 5 to 7 rounds. So, I sold it! As I get older I have noticed my recoil tolerance has dwindled!!!

Regards
Mark

Norma Ammunition recommends the following velocities for .505 Gibbs reloads:

Woodleigh FMJ 525 gr @ 2277fps
Woodleigh RNSN 525 gr @ 2415fps

http://www.norma.cc/en/Ammunit...ta/505-Magnum-Gibbs/

It never fails, somebody asks a question about the 500 Jeffery and everyone chimes in with "well, in my 505 Gibbs blah, blah, blah....

Chuck, if you want load data for your Jeffery, check the following link at RealGuns:

http://www.realguns.com/loads/500jeffery.htm

I know you prefer the heavier bullets but They are really not needed. The 535 grain Woodleigh softs zip right through bison and I am willing to bet the the 535 grain Barnes solids would zip right through an elephants skull.

quote:

Originally posted by chuck375:
My question is this, in the book "Any Shot You Want" it lists the max pressure for the 500 Jeffery at 40,000 but the 500 A2 at 63,000. Is the Jeffery max pressure based on older rifles, or a weakness in the case design, or something else? If it's simply older rifles I could get more velocity safely by going to IMR 4350, not that I need it.
Just wondering ...

Yes the pressure limits on the 500 Jeffery are CIP specified for old guns made on standard M98 Mauser's opened up,
to be safe in all rifles likely to be encountered.

The CZ 550 Magnum can certainly handle a lot more.

CIP Max Average Pressures:

500 Jeffery: 3300 bar = 47,500 psi (if 1 bar = 14.5 psi, about 1 atmosphere of barometric pressure)
505 Gibbs: 2700 bar = 39,150 psi

A-Square:

500 Jeffery: 41,364 CUP or 47,170 psi by their conversion
505 Gibbs: 34,833 CUP or 39,187 psi
500 A-Square: 55,152 CUP or 63,860 psi

Fret not about your CZ 550 Magnum chambered for 500 Jeffery.
The 500 Jeffery has about 10 grains greater water capacity, bigger case than the 500 a-Square.
You can equal or beat the 500 A-Square with it at lower pressure, if the throating is the same,
and if we wish to work up a proper load to do that.
The action can handle even the greater bolt thrust of the 505 Gibbs at about 55,000 psi for regular use, approved by CZ,
even though the CIP and A-Square spec is for only about 39,000 psi for that one.

Now my question:
What kind of throat is CZ putting on the 500 Jeffery they build?
The CIP chamber has zero parallel-sided free-bore.
It is just a funnel-like leade.
The way I read the chamber drawing by CIP, throat starts at 0.5110" diameter where the case mouth chamfer ends,
and tapers down with a leade angle of 0-degrees-47'53" (about 3/4-degree) for a run of 0.4098" length of throat to taper down to .5000" bore diameter.
That is a pretty tight and short throat.
No seating-out-long-nose options with any bullets.

You might want to keep it down to 2300 fps with 570-grainers if it is throated like that.
But keeping pressures to about 60,000 psi should be no problem, and harmless to your CZ 550 Magnum rifle.

Be a good chap and seat a flat-based bullet backwards in a fully re-sized 500 Jeffery case,
and see how much of that base can be hanging forward of the nose and still chamber the dummy round.
You can get a feel for the throating that way.
Mark the base of the bullet with a black Sharpie indelible marker, and you can see the rifling land marks on the bullet when it makes contact.

Hi Rip, I seat my TSX's out to 3.63" OAL and have over .10" freebore which is fine with me. Dave if I'm feeling manly I'll try some of those realguns load with IMR 4350.

Thanks to both of you.

Chuck

I have both a 500 Jeffrey and a 505 Gibbs.

As has been said, Recoil over that 2300 is not worth it as animal die very well at below that.

Agree and thanks!