Molds for Mauser .318" J-bore?

[Bigslug]

Don't own one or plan to, but curious for the sake of another. . .

Neither NOE nor Accurate appear to list a mold design appropriate to the 88 Patrone cartridge with the .318" bore, which I find a little puzzling, as this issue has almost certainly come up plenty of times. The obvious answer would be to pick a mold from Accurate with appropriate base and lube groove profile and have Tom fiddle the diameter up or down according to your chamber slug, but the apparent lack off a ready-to-roll option baffles me a bit.

So. . .what all are you using?

[Harter66]

I looked for some time myself . I had an 8×39 ........it didn't start out like that I'm sure , but the barrel was .305×.3165 . A fired case would press fit a .323 with a .318 nose and the front band sticking out with a 323-175 Lee .

I ended up sizing those .318 or patching a .310 to .317 and ironing it down to .317 . I would expect that the 8mm J owners are doing the same with 323-325 moulds . You're kind of in the same boat with .270/6.8 moulds , there are a few available but there are more 7mm moulds and everyone makes an standard/oversized light , medium and heavy .

[KCSO]

Just use any 324 mould and use a push through sizer to what you need. I have ran 324 to 317 for a 303 with no problems.

[Ronald]

Many .318 military rifles had the grooves deepened so they could use the .323 ammo. The 8x60 Mauser has a .318 bore but uses .323 bullets with deep grooves.
I would slug the bore to see what you really have before doing anything. I had a .318 Sauer drilling that was very happy shooting PB cast boolits that dropped at .320.

[Outpost75]

Many of the J-bore rifles converted for S-bore ammunition didn't have the grooves deepened at all, but rather had the neck clearance diameter increased and the forcing cone angle reduced to ease the extrusion force to engrave the larger bullet. Most of these barrels which I have slugged have been .320-.322" in groove diameter, the same as for the .32-40 Winchester and .32 Winchester Special and cast bullets intended for those calibers work well.

If you wanted a heavier bullet of shorter length in the body, better suited for the shorter neck of the 7.9x57, and having a larger diameter, tapered forepart, fitting the Mauser type throat, Tom at Accurate or Veral Smith at LBT can easily do this for you. If there were sufficient demand I'm also confident that Swede at NOE would be happy to do a group buy for a .320-299 or similar.

This is the bullet Veral cut for my 8mm:

Attachment 210994

[junkbug]

They are out there, if not a little pricey.

https://www.buffaloarms.com/319-220-...d-jim2319220gc

[Multigunner]

Some early gunsmith assembled sporting rifles built on the GEW 88 action did have a .318 bore size, but these were intended for lead alloy cast or swaged boolits only. The steel of the barrels was soft compared to the standard mil spec barrel. They lack the German proof marks denoting suitability for metal clad bullets. IIRC the actions are of the earliest type and don't have the modifications that prevent double feeding and other safety concerns.

[Krag1902]

Ideal made a mold for the J bore, the 317202 180. I'm not a fan of the Kephart designs but I found this one-piece Ideal mold in the original box and the last Tulsa spring show for cheap and brought it home. Cool.

[EDG]

GEW 88 and KAR 88 rifles in 8X57j were designed to shoot .318 bullets.
HOWEVER the groove diameter is NOT .318. It is .320 to .321. The two that I own are .3205.
So you really need a mold that casts about .322 to .323.....

[Mike67]

I use the Lee 324-175 mold sized to .321 and it works just fine with no leading in my pristine j bore.