How many cases need to fail before there are too many?
I'm sure I am only neck resizing. There is an eighth inch gap at the resizing die (estimated, I can measure if needed). However nearly all of my rejected cases are for signs of head separation. Any Ideas?
Gene

What method are you using for testing the cases? Are you feeling the inside with a sharp probe or are you looking at a bright ring on the exterior?

Some plastic bullet boxes rub a ring on the case right where it would fail if it were true head separation.

Look closely at the neck after sizing to make sure it didn't size down to the shoulder, too. Could be a defective die.

What caliber and action type? Are the cases shot exclusively in that gun? More info would be helpful.

quote:

How many cases need to fail before there are too many?

If it's after 1 or 2 firings one separation is too many. (assuming you're firing virgin brass and not something you picked up at the range.)

I heartily advise you have your headspace checked. This seems like an unusual condition.

The rifle is a Rem 700 BDL SS in 30-06.
The load is very moderate 54.5 gr IMR4350 WLR primers RP brass and 165 gr Hornady BTSP.
The cases are only fired in this rifle.
There are visible cracks on the outside.
I'm finding them by feeling with a paper clip and confirming with destructive inspection.
They have been reloaded three to five times and none have been rejected for any other reason.
I'll look over some rounds to see if I can tell how far down the neck I'm resizing.

Is this a new rifle or new to you? It really sounds like a bad chamber (headspace) or bad dies.

I am assuming they're a single circumfirential crack like a genuine case separation and not vertical?

Either way I'd have it checked by go-no-go guages and a chamber cast if necessary. Maybe you can fire a few factory round and measure them before and after?

since headspace has already been mention, the other thing is a bad die set. I've seen it where a 6.5 sizing die knocked the nect down to .250 and then the expander brought it back, which caused all sorts of split neck problems.

How much is base diameter expanded after firing, compared to factory cases?Ed

I bought the rifle new in 1999.
Yes, the crack runs around the case just above the head.

Ed I still have some of the original rounds purchased with the rifle. The new ones are 0.004 smaller where the heads are stretching.
Gene

Do a chamber cast, then measure it's diminsions.

You can purchase cerosafe to do the job from various sources, including Brownell's.

All your questions will be answered if you follow this procedure.

Jerry

Gene-How small is case base diameter after you resize compared to the originals?And compared to
the nominal .470 base size for 06?Ed.

It definetly sounds like you have an excessive headspace proble. Either your dies or your chamber is causing this. Try sizing your cases so they just fit in the chamber. I would have a good gunsmith check it w/ a go guage & see whats up. If it's the chamber, no big deal to have him bring it in a couple of threads & rechamber.

My fireformed cases measure 0.469 as does my resized brass. I'm sure I'm neck sizing. However when my brass fails it's at the head.
Gene

That's pretty weird. If you know you're just neck sizing and the cases still fail then tha chamber is so long that 90% of the damage must be happening on the first firing. I'd cast the chamber and see what I had.

tigger,
I've been looking over some brass and think I see how far the sizing die is coming down the neck. There is a change in the surface just above where the neck meets the sholder. I'll see if I can measure it.
Gene

My resized brass measures 0.332 on the outside of the neck where the books say 0.339. just before the shoulder it steps up to 0.340.
I measured some other brass that was resized with the same die. I don't have any unloaded brass from the set that is separating at the head. I just reloaded all that I could.

I just reread my posts, my cases may have been reloaded more than 3-5 times that number seems conservitive now.

For a quick check of headspace put a layer of
"Scotch" tape on the case head. You may have to pull the bolt to get it under the extractor. Add layers until you can just feel the shoulder touching. Put two layers of tape together and mike them, that is your headspace.
If you have headspace and reload backing off on the resizer will be a fix.
Good luck!

quote:

Originally posted by Gene:
tigger,
I've been looking over some brass and think I see how far the sizing die is coming down the neck. There is a change in the surface just above where the neck meets the sholder. I'll see if I can measure it.Gene

Lube a fired case for sizing. Then take a match, and "smoke" the neck and shoulder before you size it. This will show you EXACTLY where the die is touching the case neck and if the shoulder is being contacted (and shoved back) when you size with the die adjusted as it has been previously. If the shoulder is being moved back in any way, this could be the cause of the case head separations.

Of course, excess headspace could certainly be present, but it you have excessive headspace, the cases should be fire-forming (shoulder moving forward) on the first shot, and if the shoulder is NOT being pushed back on resizing, the case should have stretched only ONCE, which might lead to a failure later, but not as soon as your cases seem to be failing. I have never seen an incipient head separation due to excessive radial expansion of the case (from a too-large diameter chamber) but suppose it COULD happen.

IF you have some means of necking a couple of your cases all the way up to .338" or even .358", then you could neck them back down a little at a time, creating a "false shoulder" on the case and testing the cases in your chamber until you reach the point in sizing them back down that will just permit you to close the bolt with some force. When you reach this point in the necking-back-down process, examine the cases. If your rifle has excessive headspace, the rifle will permit you to close the bolt before the "false shoulder" is completely sized back down, and this condition will be totally obvious!

A good strong rifle like yours should not be permitting case head separations to develop. An old SMLE in .303 British, yes! But NOT a Remington 700!

Gene,

Even if it's the handloads there is plenty of suspicion that the rifle has too much headspace. Take it to a gunsmith and have it checked. I would not sell the gun either in that condition.

For a do it yourselfer like myself I would buy a no go gage from Foster and see where I am headspace wise. If it takes a .005" shim over the no go it's too much for me.

If it were a better make I would neck up 280 Remingtons and set the cartridge headspace to fit the rifle.

Since that is a SS rifle it may be new enough to interest Remington in free warrantee work to fix it.

If the rifle had a headspace problem wouldn't it show up on most or all of my brass? My latest batch was 90 rounds. 2 of the cases failed. I'm of the impression that cases will fail eventualy, I just thought they would fail by splitting at the neck.
I'll see my gunsmith Monday.

Gene