Case Separation 223R

[madang55]

A mate of my son-in-law has recently gone deep into the rabbit hole, reloading. He is not a bad shot at all, and is very meticulous with his reloading, but..His 3 time loaded Norma cases are showing bad signs.

Screenshot_20260707_122008_Messages.jpg (247.32 KiB) Viewed 93 times

[bladeracer]

Wow, how hot is he running them? And what is the rifle?

[madang55]

A Lithgow. Dont know his loads, but I did suggest this shouldn't happen with newish Norma brass

[bladeracer]

A Lithgow. Dont know his loads, but I did suggest this shouldn't happen with newish Norma brass

Yeah, it's surprising.

[Wapiti]

I don't reckon it's surprising at all.
Most people it seems, use standard inexpensive die sets, that have only an FLS die. Hey, no problem there.
BUT>>> Anyone who sets up these dies as the instructions say - adjust the die to cam the shellholder over at the top of the ram stroke when sizing - I'd bet is shortening the case WAY under-length.

Ask the dude before he blows the gun up how he is doing it, at any rate.

The ONLY way to set up a FLS die is with the rifle there with you.
Start the FLS sizing by backing the die off maybe two turns up and out from the shellholder hitting the bottom of the die, and try the case in the chamber, see if you can close the bolt. Don't force it.
Keep sizing the case, maybe by screwing the die down half a turn at a time, until it does. Then put that case aside and lube up another one. It will be shortened too much, most likely.
Then with the second case, back the die OUT a quarter of a turn, size it, and see. Keep doing this, bit by bit, until the case allows the bolt to close. The case should chamber with some slight "feel", which tells you that the shoulder is centring in the countersunk shoulder and is a perfect fit. You actually want it a thou or two long, so it stretches SFA.

If that's what happens with the best brass, after three reloads, he is OVER sizing the cases - i.e. shortening them into a sloppy fit so the blow back at the head, forwards at the front and thin out the middle. Until, BANG. Out the back as well as out the front. Great fun.

[Wapiti]

Remember, if you only partially FLS a case, say just halfway down the neck, the case actually lengthens a little, until finally the case contacts the inner shoulder of the die and starts getting pushed back.
Anyone who uses a shoulder bump gauge and good dial calipers will know this as fact.

So you can use an FLS die to actually better centre the reloads you make in your rifle's chamber, to better centre the projectile as it hits the rifling, better than just neck sizing. That is a fact, and any advice other than that comes from repeat BS said so much it becomes fact. But it aint.

That's why Uncle Nick's reloading book is so good, it explains this in detail. It's a great book.
Those with the gear can do these experiments and actually see how true this is, measurements with gear that allows you to do this doesn't lie.

[deye243]

I don't reckon it's surprising at all.
Most people it seems, use standard inexpensive die sets, that have only an FLS die. Hey, no problem there.
BUT>>> Anyone who sets up these dies as the instructions say - adjust the die to cam the shellholder over at the top of the ram stroke when sizing - I'd bet is shortening the case WAY under-length.

Ask the dude before he blows the gun up how he is doing it, at any rate.

The ONLY way to set up a FLS die is with the rifle there with you.
Start the FLS sizing by backing the die off maybe two turns up and out from the shellholder hitting the bottom of the die, and try the case in the chamber, see if you can close the bolt. Don't force it.
Keep sizing the case, maybe by screwing the die down half a turn at a time, until it does. Then put that case aside and lube up another one. It will be shortened too much, most likely.
Then with the second case, back the die OUT a quarter of a turn, size it, and see. Keep doing this, bit by bit, until the case allows the bolt to close. The case should chamber with some slight "feel", which tells you that the shoulder is centring in the countersunk shoulder and is a perfect fit. You actually want it a thou or two long, so it stretches SFA.

If that's what happens with the best brass, after three reloads, he is OVER sizing the cases - i.e. shortening them into a sloppy fit so the blow back at the head, forwards at the front and thin out the middle. Until, BANG. Out the back as well as out the front. Great fun.

On a 7/8X14 die I do it 1/16 of a turn equals about 0.001" works every time don't do it very often because I mainly neck size .
everything I own has a neck sizing die Plus a body die

[bladeracer]

On a 7/8X14 die I do it 1/16 of a turn equals about 0.001" works every time don't do it very often because I mainly neck size .
everything I own has a neck sizing die Plus a body die

I have so many collect neck dies, because I thought that was the way to go. But eventually I learned that for most rifle chamberings you can only neck-size so many times before you have to bump the shoulder anyway. It makes more sense to me to simply bump the shoulder the same every time I load the case for consistency.

[Wapiti]

I don't reckon it's surprising at all.
Most people it seems, use standard inexpensive die sets, that have only an FLS die. Hey, no problem there.
BUT>>> Anyone who sets up these dies as the instructions say - adjust the die to cam the shellholder over at the top of the ram stroke when sizing - I'd bet is shortening the case WAY under-length.

Ask the dude before he blows the gun up how he is doing it, at any rate.

The ONLY way to set up a FLS die is with the rifle there with you.
Start the FLS sizing by backing the die off maybe two turns up and out from the shellholder hitting the bottom of the die, and try the case in the chamber, see if you can close the bolt. Don't force it.
Keep sizing the case, maybe by screwing the die down half a turn at a time, until it does. Then put that case aside and lube up another one. It will be shortened too much, most likely.
Then with the second case, back the die OUT a quarter of a turn, size it, and see. Keep doing this, bit by bit, until the case allows the bolt to close. The case should chamber with some slight "feel", which tells you that the shoulder is centring in the countersunk shoulder and is a perfect fit. You actually want it a thou or two long, so it stretches SFA.

If that's what happens with the best brass, after three reloads, he is OVER sizing the cases - i.e. shortening them into a sloppy fit so the blow back at the head, forwards at the front and thin out the middle. Until, BANG. Out the back as well as out the front. Great fun.

On a 7/8X14 die I do it 1/16 of a turn equals about 0.001" works every time don't do it very often because I mainly neck size .
everything I own has a neck sizing die Plus a body die

A great example why I said, say, half turn until you get nearly there. Because if someone does it a thou at a time when they have to go 80-120 thou (around 2-3mm from the start point example) you'll need another haircut in between starting and getting it spot on. Certainly I don't have that sort of time or patience, and that's not being a smart-arse so please don't think I'm trying to be one.
You (well I do) start the fine adjustments when you just about get there.
And not being able to see inside the die, knowing how much to move the die in/out is irrelevant, you don't know till you get there eh.
I also mentioned the two-die sets because from what I've seen with average reloaders (farmer mates and city based mates), not nutjobs like me who use micrometer and competition dies, they have these two die sets and not having a neck die, if you realise how using a FLS die correctly to centre your reloaded cartridge in a tapered, bottle-necked chamber, you are actually giving your projectile a more centred and therefore straighter presentation into the rifling.
Because it doesn't happen slowly, it happens in a millisecond.

Anyway, I reckon I've made my point. Good luck to the mate of the SIL, I've made a suggestion, take it or not.