Copied from my post in the reloading forum:

After experiencing my first head separation in more than 40 years of reloading, I've decided my Zastava 9.3x62 has excess headspace.

I rang a gunsmith and was told fixing it would cost at least $250. At my age I'm not sure I want to spend that so decided on another approach.

My answer was to buy new Norma brass, which is about .005" fatter at the head than Winchester's. This fills the chamber better, which I feel may also remove some stress at the web.

Then I bought an 8mm Dynabolt (expanding fastener for brickwork, cost 76 cents) and shortened and bored out an old 375 Win case to make a ferrule between the case mouth and the nut on the end of the Dynabolt. The ferrule is about 3/4" long but the length is not critical.

I insert the Dynabolt well into the case neck and snug up the nut until the ferrule stops against the case mouth. I then get pliers and tighten the nut about one and a half turns of fair resistence. In doing this, the expanding collar pulls the shoulder forward, after which the cases fit the chamber with good compression, less work I feel than necking up to .375" and then back down to c. .366.

I'm lucky that the 8mm Dynabolt works with this calibre. The next one down is 6mm, so would probably only work with a .270 or 7mm, not a .30 or .338.

quote:

8mm Dynabolt

so you used the device to pull the shoulder forward making the cases longer?

That's a thought, Rich, and thanks for mentioning it.

My intent was just to distort the shoulder but checking the case lengths, yes, they do measure .005" longer than the original Norma cases, though I believe I've moved the shoulder near the neck at least .008" forward.

The Norma cases are originally 2.435" but become 2.440", just short of Nosler's drawing's 2.441 and 9 thou longer than ADI's trim length of 2.431.

So, yes, that will add another process sooner and questions the saving in labor over necking up then necking back, though I wonder if that might also lengthen the case.

However, short of pushing in some pointed .375" bullets, I don't have any means of enlarging the necks on hand.

A friend has mentioned a process of putting a bump inside just one side of the shoulder, and I guess that would have less tendency to lengthen the case. How to make that gadget will have to be investigated.

PS: is there any chance that the crush fit I have achieved in the chamber might shorten the case again by a thou or two or that the Zastava chamber's neck might also be longer than expected? I'm thinking here that if their reamer was stock standard but taken 8 or 10 thou deeper than it should have been, then case length may not be critical as expected.

I might have to find some Cerrosafe and measure the length of that chamber's neck.

Well, guys, I got some Cerrosafe and checked the length of the chamber's neck and it came to .315" by my measurement. That's nine thou longer than the Nosler drawing's .306", about 30 thou longer than Winchester factory-round cases and 20 thou more than Norma virgin brass.

Thus, I believe the Zastava reamer was of the correct shape but had just been taken into the barrel .009" farther than 'ideal', or maybe .006" more than usual.

The necks of my Norma cases after the Dynabolt treatment were actually 10 thou shorter than before, even though it stretched the overall case length by about five thou.

So, the resulting .284" neck will allow a few reloads before needing to be trimmed - the neck length increased about .003" after firing, about 10% of the space available.

Therefore, I'll assert that my 'invention' does save time compared with necking up and back, and will work the brass less in the process.

Annealing the shoulder-neck area before your "process" may assist both in neck length/case length
and definitely add to case life.

No annealing equipment needed. Old candles and a pair of gloves will do it. Place the very hot cases
on a wet terry cloth, when cool-you're in business.

You guys are all making something simple, into a brain surgery lesson.
I said on the other post about this, that I would make you an expander plug for a Lee Universal Expander die, which cost like 12 bucks.
The length of the chamber is immaterial; you just make the brass fit the chamber.

Thanks 450 Fuller, I haven't perceived any problem with my method so far but might give that annealing a go.

Apart from my making the ferrule to go over the Dynabolt, dpcd, I don't think my method is as much work as what you're suggesting. Using a press for re-necksizing would be more precise but I've had no trouble so far, and one step does the lot.

Having borrowed the Cerrosafe, my entire outlay on the project has been all of about US50 cents. The Dynabolt will wear out eventually, at which time I will spend another 50c. The problem with getting things from America is the postage. Despite the much-loved competition over there, US postage is the dearest from anywhere I've ever got stuff. I bet it would cost more than the expander die and take another three weeks, but thanks for that offer.

As I said, my solution only works for the 9.3 with the 8mm Dynabolt. A 6mm Dynabolt might work for a 6.5, .270 or 7mm rifle but someone with a crook .30-06 would be out of luck as they don't make a 7mm size.