doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Junghans & Kriegeskorte 16ga x 8x57JR drilling

The 8X57R/360 case Rim diameter should be in the vicinity of 0.483" - 0.485"

Cheers,

Raimey
rse

Ohhhh, the plot thickens then. Looks like I found bad data for the 360NE. But everything on the internet is supposed to be true! =:3

Referencing the CIP drawings for each cartridge:
https://bobp.cip-bobp.org/uploads/tdcc/tab-ii/8-x-57-ir-en.pdf
https://bobp.cip-bobp.org/uploads/tdcc/tab-ii/tabiical-en-page33.pdf

It looks like the 8x57JR rim is ~.524, while the R360 is ~.488 as you say. This thing is definitely larger than .488.

But it was my shotgun ammunition that arrived today. The 8x57JR brass and the 16ga load-all conversion parts are tomorrow. Aaaaah, the wait!

I did do some "function testing" (chores, chores) on the shotgun barrels, though. Hoooo boy those clays were poofing.

Carefully posed ammo pr0n shot, including some ridiculously expensive properly-headstamped .32-40 Ballard that I can't shoot and reload with the Holy Black until I fix that other gun. Grumble.

Is the rim diameter for the 8X57 IR 13.5mm?

Cheers,

Raimey
rse

13.32, according to those CIP drawings.

My brass came today. It's most definitely 8x57JR.

I slugged the bore, but I put my caliper down somewhere after I measured the rim recess and now I can't find it. Ah the life of a hoarder. Grumble. :P

Well lovely then. Which 13 gramme bullet are you going to choose?

Cheers,

Raimey
rse

Just a caution, but reaming safely will be decided by the thickness of the barrels just past the present forcing cone. I have seen some barrels which just did not measure enough thickness to risk the pressure, and other who had plenty of "meat." If you are lucky, then it makes all the difference in the loads you can accommodate, but for peace of mind, have it measured. Of course, lower pressures always do the gun a favor. I would recommend a standard short forcing cone if you do lengthen the bores, as a long forcing cone in my experience will always lower the pattern or shot (or strike of a slug) 6 inches in every drilling I ever used one in. In one case I did it on purpose because the gun shot high. Glad there is no pitting--one less thing to worry about. Great find for the price! Keep the hinge greased and it may outlast you. Congratulations!

I'm going to leave the chambers alone. I've bought a case of 2.5" RST ammunition, wads, and a 16ga conversion for my load-all.

I'm not sure yet.

Woodleigh makes a 200gn .318 round nose that would be appropriate, but they are extremely expensive.

The 200gn Lapua D166 (.311) that I load for my M39 could probably be paper-patched to .318, but I hate to do that for a number of reasons. And it's a FMJ anyway.

There's a guy on another forum that's offered some powder-coated cast bullets that mic about .318, but I'm not sure I want to rely on that always being available (I don't cast, myself).

It would only take a couple of boxes of the Woodleigh bullets to pay for a swage die to size various of the .323 options down to .318. Probably the Speer 200gn flat base SP. This is probably the most cost effective option over the life of me and the gun.

We'll see, though. I still haven't figured out where I laid my caliper! Heh.

Mr. Polecat,
It not hard to size .323"( cup and core, not solid or partition) bullets to .318", or anything between. This would give you great flexibility. Check with LEE for affordable bullet sizing dies.
Mike