307-356 Winchester

[Spooksar]

So I have a 356 Winchester on the way, impossible to find brass in Canada for it. Managed to find two bags of 307 Winchester at a local store. Ran it through a 338 Federal due then a 358 Winchester die. Now will anneal and load it.

[skeettx]

Should work quite well
Tomorrow I will be testing my Win 94 Big Bore in 375 Win
Mike

[cwlongshot]

Yup your fine!

Same around here!! I have as many re formed 307’s as i do 356 labeled brass!!

CW

[g26]

You can form 307 and 356 from 444 marlin to...

[AnthonyB]

And don't neglect regular 308 Winchester brass necked up. It works fine in both of my 356 rifles.
Tony

[EDG]

I neck up .308 brass to make .358 Win. My RCBS dies came with a longer tapered punch to do that operation.

[Spooksar]

You can form 307 and 356 from 444 marlin to...

That’s nice to know now that Starline is making 444 Marlin brass. Even 307 Winchester brass can be hard to find. Thanks for the info

[Der Gebirgsjager]

You've got my curiosity aroused, as although I believe you, it shouldn't work so well. The .307 and .356 are rimmed cases and the .308 is rimless.
So, since rimmed cases headspace on the thickness of the rim, not present on the .308, you must be headspacing on the shoulder. Also, I would anticipate possible trouble in extraction and ejection, but perhaps the Win. BB's extractor is springy enough to get a purchase in the extractor groove of the .308 case. Anyway...no problems?

DG

[DonMountain]

I have both a 307 Winchester and a 356 Winchester rifle (Model 94 Big Bores), and both cases are more like a semi-rimmed case. I guess so similar to the rimless cases of 308 and 358 that both of them work fine through my rifles also as the extractor grabs both of them without any trouble. But I bet they are headspacing on the shoulder anyway. With my lead bullet loads running a relatively low pressure for the 308 I can fire them in the 307 Winchester without any problems. And it ejects them just fine.

[Der Gebirgsjager]

Thanks. Very interesting. Never heard of this before. I've got a .356 BB, but made the investment in a good supply of brass once time when it was on sale, so have never needed to experiment. Good information to file away in case of need someday.

[AnthonyB]

I am late in responding to this one, but think DonMountain nailed it. The extractors on both rifles handle the rimless brass with no problem and I have had no problems with case separation so headspace is apparently good. I bought a good supply of 356 brass as well, but haven't found any "need" for it. I do have a couple boxes of brass from factory ammo that I used to carry when hunting, but the 308 has been all I have used for the last several years.
Tony