Can you form 6mmBR cases from 308 brass?

Jim

If you section a 308 case and a 6BR case, you will notice that the 308 is conciderably thicker walled as it gets down toward the web. Also, the web its self is also thicker when measured from the face of the case to where the solid portion ends.

That means you would end up with a case with quite a bit less capacity than a true 6BR case. How much more, I do not know, but you might end up with the capacity somewhere between a PPC and a BR.

Tell you what. I have both at my shop. I could cut a 6BR off at the shoulder, and then cut a 308 case the exact same length, and see just how much difference there is...........jackie
 
Thanks Jackie,
That is why I asked the question. I was afraid that the capacity would be reduced.
It would be super if you get a chance to section those cases.
I could do it but I only have 10 6mmBR cases now and don't want to loose even one.
Jim
 
About this question, would the difference in primers (largeXsmall) cause
pressure problems or even accuracy problems?

Liseo
 
Why in the world would you want to make Br cases out of 308's. Heck forming cases is what killed the cartriage for years. Buy Laupa and be happy...and mentally healthier.

Hovis
 
If a 6 BR is Overbore

this may be a solution to reducing the capacity. Anything seems possible when it comes to making cases. There are some pictures around of a .22 in a BMG case cut down to a an inch and a half or two inches. If one was to bore the shouldrer - neck area out to allow an easier time of forming the Shoulder it might go better.

Lots of folks make 44MM cases from 308 cases without much trouble or consequence. I have made lots of them. I don't see any reason the cases can't be pushed back a bit more and still be usable.

For the longer cases, I have not been able to see any difference in accuracy large primer VS small primer. Small primer pockets tend to stay tighter in the Lapua case, at least but the USBR cases are a different story.

It might be a fun exercise to make 5 or 6 just to see; something to do to shorten the winter. Doing it in that manor might soften up the critics analysis of your project. :D
 
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Hovis,
I'd prefer to buy the brass, but everywhere I have checked so far has been out of them. Sinclair will not even take a back-order for them.
If you have a source, I'd appreciate know where it is.
Jim
 
HovisKM

If I live in the country who is the shooters paradise(USA), I cant see any reason to make 6 BR cases from .308 Winchester.
But try be a rifle afficionado in some countries in South América:mad:
I even saw some guys make .380 ACP cases from .223 Rem. cases.:eek:
Life is good (and easy) in USA.

Liseo (from Shooters hell)
 
Now, that makes more sense. I make some shortened cases (22PPC based) but they are not as drastic as a 308 to 6br. If you can get some things like dies imported easy, then Butch Lambert's form dies are the ticket. You can use them to push back and form a lot of cartriages. You could contact Kelbly's as they have a lot of experience exporting items.

Our good ride may be over up here....with Obama Hussein in power...

Hovis
 
I just happen to have a RCBS set of forming dies to take a 308 to a 6br. A better choice is to use 250/3000 brass, (if you can find it)
 
I have a forming die that uses a series of bushings. Homer Strickland put it together for me. If a guy has enough bushings, he can form most any case.

Hey Hovis, Alaska might be kind of far away, but thankfully we don't have to deal with import regualtions to get stuff up from the Lower 48 (AKA Outside), yet.

Jim
 
This is the 22 Zombie Killer. It is made with a shortened 458 Lott case shortened to 1.050".
DSC02272.jpg


Butch
 
Holy stumpy cartridge case Batman!!!!! :eek:
Butch don't tell me that you ever fired that Zombie Killer, did you??
This is all fun stuff, the experimenting and making do with what materials are on hand.
Very Cool.
Jim
 
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Finally Got Around To It

I parted a 308 and a 6BR to the exact length as measured from the head,, (just at the edge of the 6BR shoulder), and here is what I found.

The BR Case weighed 112 grns empty. filled to the edge with a very fine grn powder, it weighed 139 grns.

The 308 case weighed 130.7 grns. filled with the same powder, to the edge, it weighed 154.8 grns.

That is a difference of 3 grns less capacity in the 308, give or take a little.

Hope this is helpful........jackie
 
Thanks Jackie,
That is about a 10% reduction. If nothing else a person sure should approach with caution if they started loading a 308 case formed into a 6mmBR.
Thanks to the contact I got from you guys, I am going to be able to get a hold of 100 Remington URBR cases.
Jim
 
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