Friends-

I handload .300 RUM for myself and my brother-in-law. He gave me some fired brass and of the approximately 10 rounds two had split necks and this was twice fired brass.

Being that the brass was only twice fired does anyone have a clue as to what's going on hear? The brass is Remington and is regular brass not nickle plated or anything.

Does the brass need to be annealed?

Your thoughts or suggestions will be appreciated.

Just some suggestions.
One, if the loads were really hot, I suppose conditions could be just right to split case necks that quickly. Probably brass that was not annealed correctly.

They can be annealed, by standing cases up in a pan of water so that the case is 2/3-3/4 in the water. Heat the case necks one at a time, as evenly as possible, until they are cherry read. As soon as they reach cherry red, tip them over in the water.

The best idea is to simply buy some new brass and start over, you probably just got a bad batch, but I'm guessing.

maybe it's just Remington brass.

Check the outside neck diameter of a resized case and then check the neck diameter of a fired case. If there's a great difference, perhaps one of those rifles has a larger chamber.

Perhaps someone will help me out with what should be execessive expansion.

Brass is fairly cheap, buy some more.

And, if you will segregate each load per rifle, that is, batch "A" brass goes with rifle "A", etc.

Then, if they are bolt actions, only neck size the cases. This will prolong the life of the brass.

But check each case carefully prior to reloading.

Just a suggestion about Bobby's recommendation about annealing, I would regulate the temperature. Heating to cherry red will soften the case necks excessively to the point where the case neck will not hold a bullet. I would not heat the necks to more than 425 degrees but keeping them in water to keep the heads from softening is a good idea.
Gravel

If you see brass cracked before firing it caused by failure to anneal resulting in stress corrosion cracking.Fired brass however introduces various variables. .Excessive chamber [neck] diameter.Excessive hardness.Excessive pressure .Excessive sizing [neck sizing too much].Or all of the above.As the man said brass is cheap.

Bill Mc & Bobby-

Thank you both for your comments and observations. I will elaborate on some of the particulars.

Load is 92 grains of H1000 with 180 grain bullets; not a screamer load for his rifle but, I will take some measurements though.

The brass was second fired brass. The first firing was factory load and the second firing was handload.

I do keep the brother-in-law's brass seperate from mine and I did only neck size the brass after the firing of the first factory load.

ANOTHER WAY TO ANNEAL CASES SHOW TO ME OVER 20 YEARS AGO. GET A BUCKET OF WATER AND PROPANE TORCH AND YOU HAND HOLD THE BRASS BUY THE MID BODY AND ROLL NECK IN THE FLAME UNTILL THE CASE GET HOT TO THE TOUCH THEN DROP THEM IN THE WATER, I HAVE DID IT THIS WAY FOR OVER 20 YEARS AND IT HAS WORKED GOOD FOR ME. ALSO CHECK TO SEE IF THE EXPANDER BUTTON IS SCRACHING THE INSIDE OF THE NECK, THIS CAN CAUSE THE NECKS TO SPLIT TO. HOPE THIS HELPS WELLS

Droping hot metal into cold water is a known method for "hardening" metals. Just heat the necks until it is too hot to hold and then set it down to cool slowly on its own.

WHAT YOU SAY IS TRUE IN SOME FARRIS METALS BUT WITH NON-FARRIS METALS,AS IN ANNEALING BRASS THE HEATING OF THE CASE IS TO STRESS RELIEF THE BRASS BY LOW TEMPERATURE RECRYSTALLIZION OF THE GRAIN MICROSTRUCTURE OF WHICH WE WANT TO ACHIVE FINE GRAIN SIZE,TO DO SO YOU USE THE LOWEST TEMPATURE ABOVE THE RECRYSTALLIZION TEMP. (ABOUT 600F.)FOR THE SHORTEST TIME. THE RATE OF COOLING FROM ANNAELING TEMPERATURE HAS LITTLE EFFECT ON FINAL GRAIN SIZE.BUT THE SLOW COOLING COULD HAVE THE ON WANTED EFFECT OF ANNAELING THE HEAD OF THE CARTAGE,THAT'S WHY DROPPING IT IN WATER TO COOL IT IS NEEDED. I HOPE THIS PUTS SOME LIGHT ON THIS SUBJECT FOR YOU. HAVE A GOOD DAY WELLS

hi all,
a couple of years ago before .221fb brass was so easy to find i bought a rcbs .221fb from .222rem. form and trim die set and it had a little booklet with it that had tips on case forming and such and one of the tips was about annealing cases and it listed two methods, 1.) heating the neck and shoulder while the case was standing in about 1/2" of water and tipping it over after it was "cherry red". 2.) stand cases in pan with about 1/2" of water and place in preheated oven at "x" amount deg. for "w" amount of time and then let cool slowly. your getting "x's" because the booklet is out in my rangehouse and i'm not going out there in the dark, besides it's cold out, 36 deg. if anybody wants it i'll post it tomorrow, thurs.
dave.

I bought 40 rounds of .300 RUM when I first got my rifle. Of that two boxes of factory 180 Nos. Partition- loaded ammo, I had two split necks.

It hasn't happened with my handloads, some of which are on their fifth loading. That's in Remington brass too.

92 gr. of H1000 give me 3150 to 3170 with a Nosler BT 180 gr. bullet, in case you're interested.

Pertinax

Please use a little common sense before following any of the "I've done this all my life" suggestions about annealing given above.

For example, do you really think that annealing a 7mag neck and a 223 neck would call for the same amount of heat, for the same length of time? I can anneal 223 cases in 14 seconds (standing in water) while my 223WSSM cases take 45 seconds!

If you want to anneal, I suggest you either buy the Hornady annealing kit, or buy some "tempilaq" at the welding supply store. This is a liquid temperature indicator. It changes color when you reach the desired temperature. You are looking for something in the 550 or so degree range. Re-crystallization takes place over quite a wide range of temperatures, so it actually is quite difficult to REALLY mess it up. Getting it cherry red is one such way.

Annealing is really the WRONG TERM for what you want to do. What we do to brass is plain stress releaving. Annealing, in it's technical meaning, is making brass dead-soft.

For complete engineering details about brass, and the relevant temperature ranges of stress relieving, re-crystallization and annealing, see this link: http://www.cda.org.uk/megab2/costeff/pub117/sec62.htm

Perhaps it is helpful to mention that 300C is about 580F, the temperature mentioned by Julian Hatcher as the upper useful limit for annealing brass.

HTH, Dutch.