i need top open some case necks.

fiver

Well-Known Member
#1
well I'm getting going a little bit on the XCB rifle.
I went down to get out the old 7X57 Rem cases I had stashed for making my Ackley and ICL cases from.
and was wishing I had something else to work with, when I remembered I had 2 boxes of Hornady's 275 Rigby stuck in a box somewhere in the brass cabinet.
after some digging around I found them in a box under some 375 win brass so now what to do with them.
I need to neck them up somehow.
I could just champher the mouths and do the normal case prep then shove them over the long tapered spud in the Hornady neck size die.
I could drag them over the size spud in the rcbs full length die [which is gonna happen at some point anyway]
I could dig out the spud I use to open 5.7 cases to insert the cores.
or I could try some fancy fire forming dealio using up some pistol powder and some grains of some sort.

which one is going to be the better option?
I would like to keep them at least halfway straight.
 

RicinYakima

Well-Known Member
#2
What I have done to minimize case run out is to full length resize in a Wilson die, then put case in a Wilson case holder and put it backways into the case trimmer. That will square up the case head. Then run it up into a Hornady type neck expander with lots of Imperial sizing die wax. It works best for me if the case head is square, shellholder is clean and square and the press ram clean. Doing 40/70 Sharps Straight from 30/40 Army cases does take some thought. FWIW
 

VZerone

Active Member
#3
Fiver if you have a 98 Mauser in 8x57 you can just load those 7x57's with a fireform charge in shoot them in the 8x57. The Mauser claw is good of this to hold the case back again the bolt should it be a loose fit in the chamber of the 8x57. I've done something like this to blow out 308 cases straight firing them in a Mauser 30-06.
 

fiver

Well-Known Member
#4
no.
and I do.
the 8 mauser shoulder needs too much work and will wrinkle when re-shaped.
I might have to bump these in a 358 win die as it is, to shorten the shoulder a touch in the right place.
 

Ian

Well-Known Member
#5
Run them up in your shortened XCB die with the seating stem out. Expand the mouth out with a long, tapered punch greased with sizing wax until it forms to the neck of the die. Put the expanding stem back in and finish it off. If you had a .304" mandrel, or whatever it ends up being inside the sizing die neck plus the brass neck walls, you could use that to form out the whole neck from the top, the only challenge is getting it pulled back out.
 

fiver

Well-Known Member
#6
okay that is kind of the opposite of what I was thinking, but it makes sense.

a trip for the body and to make sure it chambers, then open the mouth over the tapered expander.
adjust for neck tension on the bullet.
fire form. [I need to dial in the scope any way]
anneal, and start load development from there.
 

Ian

Well-Known Member
#7
Yes except leave the case run all the way up in the die while you bell out the neck as much as you can with the punch through the top of the die., assuming there's room to get a punch down in there with the stem/collet removed. That will make a belled neck, but at least the mouth will be concentric to the shoulder/body that way, then you can squeeze the rest of the neck out the usual way by re-installing the appropriate expander stem in the die and running all the brass back over that.
 

fiver

Well-Known Member
#8
well I set the case for a consistent crush fit in the chamber.
bumped them against a smaller tapered spud to open the case mouth.
run them up in the die and used a straight sided punch to just about open them against the side of the size die.
then run them all over the spud after giving the die about 1/16 turn down to size the entire neck of the case.
this was still allowing a fairly smooth chamber with a slight amount of crush right as the bolt closed.
 

VZerone

Active Member
#9
Fiver you made me remember part of an article in Handloader where Rick Jamison was writing about fitting the necks of a case with minimum clearance and one method he mentions was don't size the neck all the way to the bottom of the neck. That is if you have a long enough neck to do that. I will read the rest of the articl soon.