.500 Jeffery has 0 degree taper case body?

15 April 2001, 06:29

<R. A. Berry>

I recently noticed, in looking at chamber and reamer specs., that the .500 Jeffery (and .500 AHR?) has a parallel sided case from base to shoulder. Surprised me!!!

Does anyone have any thoughts on why this is so and whether it may cause any feeding or extraction "stickiness?"

This would decrease bolt thrust, and be a means to increase case capacity, but is this such a good idea in a stopping rifle?

------------------
Good huntin' and shootin',
Bwanawannabe, Daktari Ron

15 April 2001, 08:32

Cannon

RAB,

I just looked at my A-Square manual, and it shows the Jeffery has a base diameter of .619 and shoulder diameter of .603. According to Art, those dimensions came from a 1928 drawing he and Dave Manson uncovered, and which they were re-submitting to CIP. COTW shows .620 and .615, but it isn't the most reliable source for dimensions.

Here is AHR's dimensioned drawing of their .500 from their website; they show the base and shoulder diameters as .6194 and .6040.

15 April 2001, 09:30

<R. A. Berry>

Cannon,

Thanks for the help there. I must have seen some bad info myself. The .500 AHR looks like a great cartridge.

------------------
Good huntin' and shootin',
Bwanawannabe, Daktari Ron

15 April 2001, 18:41

bobby van der Putten

I believe the CIP now differentiates the .500 Jeffery from the 12.7 x 70 mm Schuler. This might be of interest if you ordered your barrel from Lothar Walter.

17 April 2001, 16:51

470 Mbogo

[QUOTE]Originally posted by bobby van der Putten:
I think that you'll find that 5 thousandths taper per lineal inch is the safe minimum taper for good exctraction. 470 Mbogo

13 October 2006, 16:38

.366torque

el jeffe, how close can you get to a 550 express with this?

13 October 2006, 17:00

jeffeosso

excluding the belt, the express is .589 to ~.57~, about the same.. but since I've built them both, the express is way easier to get to feed

13 October 2006, 17:03

.366torque

quote:
Originally posted by jeffeosso:
the express is way easier to get to feed

That sounds better. All is lost when the damn thing doesn't feed!

13 October 2006, 17:05

.366torque

Isn't R.A. Berry, in fact RIP?

13 October 2006, 21:44

ScottS

quote:
Isn't R.A. Berry, in fact RIP?

Yes.

14 October 2006, 05:25

DPhillips

quote:
Originally posted by .366torque:
Isn't R.A. Berry, in fact RIP?

Look at the date of the original post, April 14, 2001. RIP has changed his username a couple of times, I think?

14 October 2006, 11:31

RIP

Yep,
R. A. Berry, then DaggaRon, then RIP.
Changes in handle came with system wipeouts and re-registration.
In 2001 I didn't know my ass from my elbow.
Neither did some of the "experts" still posting here.

The A-Square manual shows a .500 Jeffery (20 degree shoulder angle) that would be closest to the 1997 Romey hybrid:
.619" base - .603" shoulder = .016" body taper
2.321" base to shoulder
.016"/2.321" = about 7 thou per inch taper

Ken Howell shows the .500 Jeffery Triebel maximums and also calls it the 12.5x70mm Schuler (wrong):
.6193 - .6031/2.3228 = 7 thou per inch taper

But of course, we now know that the 1928 Kynoch specs for the original 500 Jeffery (12.63 degree shoulder) were different from the 1940 RWS 12.7x70mm Schuler specs (23.54 degree shoulder), and the 1997 Romey Hybrid is intermediate to these, with a shoulder angle of 19.97 degrees.

However, they all have about 7 thou per inch of body taper.

I did indeed have some bad poop on the 500 Jeffery back in 2001.

Alf has set me straight on all that 500 Jeffery stuff.