Loading data for 500 Jeffery with 590gr. solids

[Carsten]

I am trying to find a starting load for my 500 Jeffery with 590gr. drive band solids.
They are from a local manufacturer and threre is no loading data available.
Normally any load for a similar weight traditional bullet will serve as a starting load for a drive band bullet but I can’t find any similar loads with the powders available here.
I can get any type of Norma, Vihtavuori, Reload Swiss and Lovex but American powders are impossible to get here.
Barnes lists a load with VV N150 for their 570gr. DB solid but I find N150 to be on the fast side.
I would like a slightly compressed load.
I have been using QuickLoad for 20 years and in my experience it is inaccurate with straight wall cases and the Jeffery does not have much of a bottle neck so I‘m not sure of the accuracy yet.
However, I can use it for selecting the proper powder and for a 100-105% load with best performance I‘m down to Norma MRP or RS70.
The percentage of burnt powder could be better though.
What are you thoughts?

 

[Carsten]

I did some load development yesterday.

It turned out that Quickload was quite optimistic about case capacity and Norma MRP bulk density.
Using a drop tube and a compressed load I needed a C.O.L of 95mm/3.7401” with the expected charge.

Max. in my rifle with this bullet is 91.5mm/3.6023”.

I am considering giving the barrel an additional 4mm/0.1574” freebore as the longer rounds would fit better in the magnum sized magazine but for now, I will leave it as it is and use a faster powder.

I had Norma 203B/RL15 and Vihtavuori N150 and in Quickload the latter would give the best loading density.

With a C.O.L. of 91mm/3.5826” and a measured case capacity of 159.5gr. water, I stopped at 108gr. N150.
This gave me 2305fps in my 24.5” barrel.

Energy: 9435j / 6959 ft-lbs

In my 10.5lbs rifle the recoil felt quite manageable and no visible muzzle flash.

I was surprised that I had less muzzle flip with this load than I have with my CZ550 458 Lott with 500gr. bullets, probably due to the straighter stock on the 500J.

 

[geoff rath]

Try to get a copy of Woodleigh's loading manual; my last spare copy has gone to Italy ...

 

[IvW]

You want about 3mm jump to the lands....

 

[Carsten]

You want about 3mm jump to the lands....

Why is that?

 

[IvW]

Why is that?

It is not a target rifle cartridge....pressure....

 

[Carsten]

It is not a target rifle cartridge....pressure....

In my 30 years as a reloader I have never heard of the need for such a big jump pressure wise.
I would say that 0,5mm is pretty much standard as a starting point and sufficient for not raising pressure.
Especially drive band bullets can be seated close without pressure issues.

I have loaded up to and including 50 BMG without having the need for more jump.

These are my first 500 Jeffery reloads though, but I have exactly 0,5mm jump now and nothing indicating abnormal pressure.

I do not need such a small jump as I am not hunting match grade accuracy, and I would have liked a little more, but this all I have unless I decide to ream the throat for a little more freebore.

Is there a reason why big safari cartridges would be different?
What am I missing?

 

[DWB]

The rule with monolithic bullets in general is minimum 2mm Jump.

A Barnes standard/guideline if I am not mistaken. But it is applied universaly in the mono camp.

And I prefer to apply a generous crimp with that in mind.

What makes safari cartridges different? The stuff on the other side of the barrel ;D

I load for minimum movement in the mag box as well, because recoil on the big boys tend to hamer the bullets deeper in with inertia.

 

[IvW]

Just sharing what works for me.....I have a 338 Lapua mag with 3.3mm of jump for 300gr bullets and it shoots 3 shots basically in the same hole.....
Big bore stopping rounds use long hi sd bullets and brass monometal solids which require a longer minimum jump......
.5mm is way too little....
I guess you have not been reloading 500 Jeff for 30 years with 570 or 600gr bullets?

 

[Carsten]

Just sharing what works for me.....I have a 338 Lapua mag with 3.3mm of jump for 300gr bullets and it shoots 3 shots basically in the same hole.....
Big bore stopping rounds use long hi sd bullets and brass monometal solids which require a longer minimum jump......
.5mm is way too little....
I guess you have not been reloading 500 Jeff for 30 years with 570 or 600gr bullets?

No these are my first 500J reloads but you already new that.

I am a very active ELR shooter and I shot 50BMG for 10 years until they were banned here.

I used 802gr. brass drive band solids exclusively and I have never had any issues with 0.5mm or less jump.
I wonder why the Jeffery is so much different?

BTW, my 338LM with 300gr. Scenars likes 0.3mm jump for best accuracy but thats is different from rifle to rifle.

Brass drive band bullets do not require a longer jump than normal jacketed lead bullets.

Barnes general guidelines recommend 1.27mm jump and then increase until best accuracy.
I believe that is an accuracy issue rather than a pressure issue.

Barnes copper bullets likes a longer jump to be accurate but they are not brass drive band bullets.
Apples to oranges.

 

[Carsten]

Update if anybody would be interested:

I talked to the bullet manufacturer today and he claims that due to this bullets design and the low engraving force, they do not see any pressure spikes even with zero bullet jump.
He insured me that my 0.5mm was completely safe.

It would be nice with some buffer though and a little more jump never hurts, so I reamed the throat for some more freebore.

While I was at it, I decided to go all the way and make use of the full case capacity.

Bullet surface below the case neck does not do any good and only takes up powder space.
I added an additional 5,5mm freebore and I can now load to 95mm with a 2mm jump.

The 7mm extra length from C.I.P. standard, gave an additional usable case capacity of 14.3gr. of water.

Loaded to 95mm with the slower Norma MRP, it should easily make 2350fps at about 40000psi with this low friction bullet.

I will probably just stick to 2300fps and an even lower pressure.

More speed is not really needed but lower pressure is always good.
I can still maintain a 100% filling ratio.

Another benefit is that I will now make full use of the long magnum magazine and that is probably the best part.

A win win situation.

 

[IvW]

Update if anybody would be interested:

I talked to the bullet manufacturer today and he claims that due to this bullets design and the low engraving force, they do not see any pressure spikes even with zero bullet jump.
He insured me that my 0.5mm was completely safe.

It would be nice with some buffer though and a little more jump never hurts, so I reamed the throat for some more freebore.

While I was at it, I decided to go all the way and make use of the full case capacity.

Bullet surface below the case neck does not do any good and only takes up powder space.
I added an additional 5,5mm freebore and I can now load to 95mm with a 2mm jump.

The 7mm extra length from C.I.P. standard, gave an additional usable case capacity of 14.3gr. of water.

Loaded to 95mm with the slower Norma MRP, it should easily make 2350fps at about 40000psi with this low friction bullet.

I will probably just stick to 2300fps and an even lower pressure.

More speed is not really needed but lower pressure is always good.
I can still maintain a 100% filling ratio.

Another benefit is that I will now make full use of the long magnum magazine and that is probably the best part.

A win win situation.

Sounds like you are on the right track....I would stick to about 23000fps for best performance....good luck

 

[Sourdough]

Sounds like you are on the right track....I would stick to about 23000fps for best performance....good luck

2,300fps is probably a little safer then 23,000fps. ;-)

 

[IvW]

Oops.....