Splitting necks...UPDATE!

I've got a 116 in 338WM and I have been splitting a substantial amount of brass (2:5 ratio of split to not split). Out of 70 reloads, 20 have split necks. Some are single splits and others have two or three splits. This brass is once-fired, though it is about 16 years old. My two brothers and my dad have all shot brass from this lot and none of them are experiencing this problem. They are shooting 73 grains of IMR 4350 while I am shooting 72 grains, both behind 225 hornady sp. My COAL is longer (3.374) than theirs, but is still short of the lands. Why is this happening? I've tried googling, but split necks almost always leads to something about cases being shot 10 plus times. Could my chamber be too big? I need to get this solved!

Thanks

jb

What does the fired brass neck(no split) measure? What does a loaded round neck measure?

Split necks measure (with cheap rcbs calipers) between 0.361 and 0.362
Non-split necks measure the same

Reloads measure about 0.354 to 0.355

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Originally Posted by jonnybullslayer

Split necks measure (with cheap rcbs calipers) between 0.361 and 0.362
Non-split necks measure the same

Reloads measure about 0.354 to 0.355

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Correction.
After holding my calipers to the light and seeing what point is touching at zero,

Split necks measure between 0.370 and 0.371
Non-split necks measure the same

Reloads measure about 0.363 to 0.364

Try this for a cheap and quick possible fix; remove the bolt and go into the chamber with a bronze brush and solvent a clean the heck out of it. Wipe dry (barrel too). Make sure to get the throat clean as well. Did that on my hunting friends Remington semi-auto and it cured the problem. Next, try annealing that old brass, neck and shoulder before your next reload. Put them base down in a pan of water to about 1 inch. Use a berz-o-matic torch to heat the brass shoulders and neck red. As you do each one tip it over into the water.

El Lobo

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Originally Posted by ellobo

heat the brass shoulders and neck red.

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Safety note :
According to my research on annealing, heating brass until it turns red means that it has become far too hot and thus dangerously weak. I don't want to start an argument here, but before you anneal, please do some additional research. The best economical way that I know of to really determine if you are heating brass to the correct annealing temperature is to use some sort of temperature indicator, such as a temperature sensing paint or stick marker.

I agree, anneal and the problem should go away.

Quote:

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Originally Posted by jonnybullslayer

Quote:

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Originally Posted by jonnybullslayer

Split necks measure (with cheap rcbs calipers) between 0.361 and 0.362
Non-split necks measure the same

Reloads measure about 0.354 to 0.355

---

Correction.
After holding my calipers to the light and seeing what point is touching at zero,

Split necks measure between 0.370 and 0.371
Non-split necks measure the same

Reloads measure about 0.363 to .364

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While this is not conducive to good case life it is probably with in specs. I am curious what the others firing these cases without issue are getting. Annealing would lengthen their life but being once-fired one would not think it necessary. I do recall reading something about the thick necks of WSM's, perhaps this is magnifying the problem.

I think that I will try annealing. I'm going to a welding shop today to get temperature marking crayon/paint. Could it be that these cases got brittle over time? They have always been stored in a cool dry place.

Quote:

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Originally Posted by jonnybullslayer

I think that I will try annealing. I'm going to a welding shop today to get temperature marking crayon/paint. Could it be that these cases got brittle over time? They have always been stored in a cool dry place.

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To the best of my knowledge, brass doesn't get brittle simply by getting old. (I am sure that if I am mistaken, someone will jump in and correct me 8) ).

The method of annealing I outlined was shown to me over 50 yrs ago and it is what I have used. I never saw a problem with it after using it for many years. I imagine if you leave the heat on for a length of time it would be detrimental to the brass. There is a slim possiblity that residue from the firing 16 yrs ago has caused a brittle condition over the years but it should show up in the other rifles which evidently it has not.

El Lobo

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Originally Posted by ellobo

The method of annealing I outlined was shown to me over 50 yrs ago and it is what I have used. I never saw a problem with it after using it for many years. I imagine if you leave the heat on for a length of time it would be detrimental to the brass. There is a slim possiblity that residue from the firing 16 yrs ago has caused a brittle condition over the years but it should show up in the other rifles which evidently it has not.

El Lobo

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I will not argue with your personal experience. If it has worked for you safely for these many years, all the better for you. I just wanted to mention my concern based on what I had learned through my own research.

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Originally Posted by thomae

To the best of my knowledge, brass doesn't get brittle simply by getting old. (I am sure that if I am mistaken, someone will jump in and correct me 8) ).

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You are correct, brass will only work harden. Metals when fresh from the furnace, particularly AL, need to age prior to machining but by the time our cases are drawn or extruded they are plenty hard and constantly annealed during the process.

I would buy 50rds of new brass; this is probably cheaper and easier than messing around with annealing, something you have no experience at. Why add another unknown to your problem. MFG your choice and see if those necks split. If it does, it is probably time for a different barrel or a run to Savage.
Best regards,
Grit

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Originally Posted by Grit #1

I would buy 50rds of new brass; this is probably cheaper and easier than messing around with annealing, something you have no experience at. Why add another unknown to your problem. MFG your choice and see if those necks split. If it does, it is probably time for a different barrel or a run to Savage.
Best regards,
Grit

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I almost bought a box of loaded ammo to try out today...at $45 a box, I think I might look for new brass instead. I have 10 of the reloads left that I am going to shoot in my brother's Ruger. If no splits, then I will have my gunsmith take a peek at my chamber. I purchased a 700 degree indicator crayon today and will attempt to anneal a few after I've had the chance to tumble them.

Anneal them dirty. It's easier to see the temp stick.

Well, I tried annealing and I must say...WOW!!!! I shot six rounds of old brass and split three necks. I then shot ten test rounds that I had annealed and not a single split! Needless to say, I went home and annealed all of the remaining brass. Yesterday I went out and shot a ladder test with 10 different loads. I repeated the test for verification and all 20 brass were beautiful. Thank you all who contributed!

I would anneal it is very easy to do. There are plenty of articles on the net to read on annealing.
On another note it sounds to me like the neck on your chamber is plenty loose and allowing the necks on your brass to expand way to much. JMHO