i had a case-head separate from the body when ejected (458 lott, ruger#1) it broke cleanly right above the belt. the cases have been reloaded approx 6-7 times with low / moderate charges.
1) is this a serious warning sign of tired cases and do i toss this batch of 20?
2) if i keep using them until failure is there a risk of gas blowing backwards at me or damage to the rifle? thanks.

There is a die you can use to minimize the problem. I read about it on another forum.

On the website below you can read about it and how it works.Belted Magnum Collet Resizing Die
http://www.larrywillis.com/
It solved my problems that were similar with a 375 H&H

I have the collet resizing die that Bob is refferring to and it does work. I usually only need to do this though if the load is a bit on the hot side.

However, the head case seperation that you are seeing is something that I have only seen in my 220 swift, and that was due to full length re-sizing the brass and shooting it in different guns.

I solved it there, by neck sizing and only shooting the brass in its selected gun.

Are you having to trim your brass every time? In other, is your brass stretching out too much?

Try just neck sizing and see if that helps.

The belted magnum collet resizing die will do nothing to prevent case head separation and in fact would probably make it occur sooner.

Brass shot in any firearm given enough reloads will stretch. How much it stretches depends on how well the brass fits the chamber and how heavy the loads are. When the brass stretches, there will be thinning near the case head and eventually a case head separation.

The geometry of the case has a lot to do with how fast a case stretches. A case with no or little taper like a 458 Lott case won't stretch as much as a tapered case like a 375 H&H Magnum. In fact, for lower pressure straight walled cases that are crimped like a 44 Rem. Mag. case, it's quite likely that there will be cracks around the case mouth from recurrent crimping before a head separation occurs.

I run a wire with the tip bent to 90 degrees (a paperclip works well) down the inside of the case. If I feel a groove/indentation above the case head, I know a head separation is imminent and that case gets discarded.

Usually when I have seen this it was do to over working the brass on a belted case. Setting the shoulder back each time and headspacing on the belt. Kind of hard to set the shoulder back on a Lott.

It might have been a bad case. While you can use the wire method to try and feel for a separation point I've grown much more conservative in my old age. You have 6 or 7 loading out of your brass. You can buy new for less than $1 each how much risk do you care to take for less than $20?

O.K. the 458 Lott is a different animal to the 303 Brit and 22 Hornet, but those two cases are very prone to head separations, the first due to the flexy actions and the second due to the absence of a shoulder to head-space on. But, I do not have any head separation problems at all. I lube my loaded cases with 'Smoke Stop'. The problem with doing this is that the stuff can get wiped off in the field. It can also help to collect dust and debris. But it not that bad. However, some say that this will increase thrust on the locking system. Not much if at all! Besides, there is no way a Ruger cannot handle a little extra thrust.

Welcome Aboard!

quote:

Originally posted by robm:
1) is this a serious warning sign of tired cases and do i toss this batch of 20?

Probably. Check the "inside" of the case with the "L-shaped" Feeler Wire that Paul mentioned. Take a Paper Clip and nip the wire off with a set of side-cutters. That will make a small Chisel Tip on the wire. Bend the wire 90deg about 3/16" from that Tip so the Chisel Tip will be Perpendicular to the long leg. Then stick it inside the Case and drag it up the inside to see if you feel the Insipient Case Head Separation(a groove) (ICHS) at the same spot your Case Separated. If you have any older Speer Manuals, this is shown inside them.

quote:

2) if i keep using them until failure is there a risk of gas blowing backwards at me or damage to the rifle? thanks.

Yes and yes. Gas can blow back toward you, especially if your rifle is a (rag) M70. And if the Case only slightly separates or creates a Pin Hole, the HOT Gas can act as a Cutting Tourch and blow a small crater in the Chamber Wall.

On Dangerous Game rifles, I normally recommend an Initial Fire Forming Load, but that is not needed on the Straight Walled Lott. So, shoot them with an initial Load and then two more times at Game, then relegate those specific Cases to Practice Loads.
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quote:

Originally posted by Grumulkin:
The belted magnum collet resizing die will do nothing to prevent case head separation and in fact would probably make it occur sooner.

Gotta agree with Grumulkin. The $100 Larry Willis tool(aka Thingy) will "squash" the Pressure Ring to a smaller diameter, but it won't do anything to help with the ICHS, because it can not "thicken" the Case at the Pressure Ring.

Best of luck to you.

Other than the straightening the crimp, there is no real stretching force applied to a straight-walled neck. Was this brass re-formed from a necked caliber? Has it shown any signs of stretching during its useful life?

I'm here to tell you that there IS stretching of straight walled cases with high pressure rifle type loads.

quote:

Originally posted by Grumulkin:
I'm here to tell you that there IS stretching of straight walled cases with high pressure rifle type loads.

If I understand this correctly, a minimally-sized necked case's stretching is somewhat controlled by the shoulder, whereas the straight-walled case is not so benefitted. Worthy of thought.

quote:

Originally posted by Grumulkin:
I'm here to tell you that there IS stretching of straight walled cases with high pressure rifle type loads.

Correct again.

The amount of stretch at the Pressure Ring depends on:
1. The physical size of the Case at the Pressure Ring. This varies slightly between Manufacturers and Lot to Lot from the same Manfacturer.
2. The physical size of the Chamber opposite the Case Pressure Ring. This varies slightly between Manufacturers and Chamber to Chamber from the same Manfacturer.
3. The amount of Cartridge Pressure during Firing.
And if it is a Reloaded Case:
4. The physical size of the FL Die where it makes contact with the Pressure Ring.

All of the above is true for any size and shape Case.

Best of luck to you all.

Now I know where all the fresh donuts disappeared to today! Hot Core got them and the sugar high has his brain in high gear.....I agree completely with him!

Larry Gibson