308 jackets

[Ervin]

I’ve been thinking about brass to 308 jackets. So I picked out a 22 mag rf and took some measurements. Now these are not exact because the case is not a consistent diameter. The rim is about .290, about .018 undersize. The base above the rim is about .245, about .063 undersize. I see some problems however.
1. Seating a core with enough pressure to expand the case to .308 without the core squirting around the .224 punch. Ithink th bottom punch would be .308.
2. Trimming the brass to a consistent length & weight.
3. The case would be very thin.
Ervin

[Utah Shooter]

Ok.. Not sure I follow?

[BLASTER62]

I’ve been thinking about brass to 308 jackets. So I picked out a 22 mag rf and took some measurements. Now these are not exact because the case is not a consistent diameter. The rim is about .290, about .018 undersize. The base above the rim is about .245, about .063 undersize. I see some problems however.
1. Seating a core with enough pressure to expand the case to .308 without the core squirting around the .224 punch. Ithink th bottom punch would be .308.
2. Trimming the brass to a consistent length & weight.
3. The case would be very thin.
Ervin

You could not core seat that case to 308 it would go past the punch or explode. You would have to draw the case to a couple of thousands of 308 and the case would proabley crack. My 2 cents..

[runfiveslittlegirl]

there's a reason they use the 22 mag for 243 bullets and not 308 bullets.

[Smokin7mm]

Not sure about 308 but I have used 22mag cases all the way up to 7mm (.284). I use an expander punch similar to the ones use to make the TCU series of cases but it expands up so the outside dia is approx .002 less. Approx .281-.282". A 25 ACP shell holder holds the 22mag case in a standard loading press and I mount the expander in the top of the die. I expand down as far as I can and still get the case out of the shell holder. I then anneal the case and remove the rim in my derimming die for my swaging press (makes 6mm jackets from 22mags). I only go in far enough to take the rim off and then use the punch to push it back out so what you end up with is a jacket that is about .241" for about the first .25" and then tapers up to .282". The bottom fills out while seating the core. Note the 7mm core seating die I have is a boat tail so the bottom of the jacket doesnt have to completly fill out. I have also made 270cal bullet tha t are flat base though using this same method.
Bret