I am the unhappy owner of a Heym Express rifle in cal. .500 Jeffey. I have gerat problems with the ammo from Kynoch it will not fire every time.About 50 % of them will not fire.
If somebody have some experience please pass it on.
I have also .500 Sch�ler from WR some of them fire good some of them are too tight but will fire.

I read somewhere (on these forums?) that there are two versions of the .500 Jeffery that differ in the shoulder angle. Perhaps that changes the headspace and your rifle is chambered for a different version than the Kynoch ammo?

I am making the assumption that you're not reloading and setting the shoulders back in the resizing operation.

Perhaps we have a fellow Dane who can help you?

There's only "one" standard 500 jeffe... but chamber could be cut wrong.

This heym a double rifle? that would be weird...

what, exactly, is it doing/not doing and have you called heym? I had a problem with primers, due to shell holders, as the 500 rim is thinner than the 416 rigby, according to design, and the primers were high

jeffe

Sounds like your chamber is too long or more likely the shoulder on your ammo is set back far enough that you don't get reliable ignition. Try the old RGB headspace trick. Take a pair of pliers wrap the jaws with cloth and just squeeze the shoulder of your cases a little bit. What your doing is producing a false shoulder. You don't want to squeeze the sholder so much that you can't chamber a round. When the cartridge chambers it should have some FEEL to it. I'll bet they go off everytime now! Now neck size only your fired brass and you'll be fine.-Rob

So, what everybody says is, "Load your own ammo, dont use Kynoch and you will be fine."

A Heym express is a bolt action as far as I know. Nice rifle, about 5-6000 Euros (6-7000 US). Mauser copy.

Jeff,



I'll see if I can find the reference which was made to the dies required. I'll send that to you via PM for comments. I'm really interested as I'm still in the raffle and want to understand the cartridge.



It sure sounds to me like a headspacing problem barring a mechanical problem with the firing pin. Of course there are too darn few specifics.



Thanks to Alf an RIP for their contribution and superior knowledge. I knew I'd seen something somewhere... (dang CRS! )

Kynoch "500 Jeffery" ammunition should follow the 1928 specification for the "500 Jeffery" chamber. It has a 12.63 degree "semi-angle" shoulder.



Two other versions of similar chambers are to be found, with slightly more pronounced shoulder:



RWS, 1940, 12.7 x 70 Schuler, 23.54 degree



Wolfgang Romey, 1997, Hybrid, 19.97 degree



The last one may be for the "500 Jeffery Improved" of Harald Wolf. Or is it just the Romey standard 500 Jeffery/12.7x70 Schuler ammo for a sloppy fit in either? I am not sure why this one exists, and dated 1997.



Anyway, all of these shoulders merge to about the same datum line at the juncture of the neck and forward shoulder edge.



The Kynoch specification ammo will be a sloppy fit in the Schuler chamber. It might fire sometimes and sometimes not.



The Schuler ammo could not be chambered in the Jeffery, if the specs are right.



You may just have a 500 Jeffery chamber with excessive headspace. Rob's suggestion should work, but I do not like the thought of only neck sizing in a DGR where effortless chambering in a hurry is desirable. And, the ability to use standard factory ammo will not hurt the resale value of the rifle.



If the rifle is supposed to be a "500 Jeffery" then there is either a problem with a too long chamber, or too short ammo from the factory, regarding headspace, assuming the primers and propellant are good.



If you have too loose a fit with 500 Jeffery ammo and too tight a fit with the 12x70 Schuler ammo, that would suggest a Romey hybrid chamber.



Anybody know why that humdinger came about? I don't.

Once you have fired rounds that work you can have CH4D make custom dies to properly FL resize the cases without setting the shoulder back. I personally don't like the 500 Jeffery as I've seen too many that have feeding problems. the famous bolt override. I'd consider the 500 AHR as a better cartridge. I also have a magazine mod that can correct this problem.-Rob

The action feeds perfectly and it is very plessent to shoot 5,6kg I would just like to know if it is a 500 Jeffery or not. I think that Heym fucked up in the chamber.
I can have a die set made for $ 200 that fits the chamber 100 % but is says 500 jeffery on the barrel and should therefor fire 500 jeffery rounds. you can e-mail me at andreflor@tdcadsl.dk and I will send you pictures of the rifle.

Cheers

Andr�

Dear Rob

Did you get my reply ( the long one)

.

Don't want to belabor the obvious, but wouldn't it be better off for you to send the rifle back to factory with several fired cases and state your problem? If you don't want to do that, then you should take it to your nearest qualified riflesmith asap.

This thing is a Heym so Heym should know exactly what they made and what ammo it was designed for. A quick cerrosafe cast will also shed light on the subject. If it were mine, I'd send it to American Hunting Rifles and have it rechambered to the 500 AHR ( an improved 500 Jeffery) and buy about 150 cases from them. That should solve the problem forever.-Rob

I would call Heym and ask them what to do.