Split Case Necks, 30-40 Krag

[Crowman]

Background:

I have a slick sporterized Krag (checked out by gunsmith) and a Browning rendition of the 1895 Winchester. I reload the 30-40 Krag, and duplicate the original military load with 220 grain Hornady .308 round nose bullets. I also had some 180 grain Winchester SP factory loads on hand, and shot them to reclaim the brass for the mild 220 grain loads. Cases are properly head stamped 30-40 Krag and are NOT Enfields. Brass was either once fired or new. Dies are by Hornady.

Problem:

Had 7 case necks split from both lots. No other problems noted, just split necks. 20 Loads were shot between both rifles, cases randomly split from both. Not sure what's happening. Haven't had the problem before.

 

[gamestalker]

Considering you are experiencing this in both rifles, I think I would pull a few and verify the powder charge, sounds like maybe a heavy charge.

If you can, post some pics of both the split necks, and the case heads.

Also, what are the specifics of the powder charge you are shooting.

Also, are you seating them close to the lands, as that can cause pressure spikes, even with charges that are well below maximum.

GS

 

[tightgroup tiger]

I would have to wonder how old your 30-40 brass is and where is came from. Brass does grow brittle with age and if these loads have been sitting around for a lot of years that may be contributing to your problem.

How old is this brass and if it were me I would re-aneal the surviving brass to see if it improves.

 

[Crowman]

About half were new Winchester factory loads (180 grain bullets). The others were hand loads using the classic 40 grains IMR 4350 under a 220 grain round nose soft point. Hand loaded cases were trimmed to 2.304 +0.000/-0.0025". Bullets were seated to SAAMI maximum COL of 3.089". Brass was once fired.

 

[joed]

It's your brass, I went through a similar thing a few years ago. Wait till you resize, many more are going to crack. You may be able to anneal it before sizing.

 

[Crowman]

Hummmmmmm, Other than old over-worked .357 magnum and .45 ACP cases splitting in the case mouth after countless reloading, these are the first rifle cases I've had to split in the neck. Never had the problem with 308, 260 Rem or 7-08. Suggestions on annealing them?

 

[RPRNY]

The 40 grs 4350/220 is as you note well within SAAMI MAP. The factory 180 grs loads at an optimistic 2300 fps aren't at issue either. That this has happened in both rifles makes chamber issues unlikely (very jealous of your M95!).

My first question is about bullets. You mention Enfields. Is it possible that you loaded .311 jacketed bullets? Doesn't explain the factory loads... That leaves us with worn brass, unlikely in first fired factory loads or poor case prep, which still doesn't address factory loads.

Pictures might help but I am stumped...

 

[Crowman]

As stated earlier, bullets are Hornady 220 grain jacketed SP, .308 diameter.

Fired cases are outside in my reloading shack, so no pics tonight. Cases are full length sized...loading for the two rifles.

The 1895 lever gun is actually stronger than the 1898 Krag, and almost cycles as fast but the Krag has better sights and faster magazine loading. Has old Redfield aperture receiver sight, front is a banded barrel hooded ivory bead job.

The bolt is slicker'n owl snot. It is unbelievably fast to cycle from the shoulder.

Never had to anneal rifle case necks before?!?!?

 

[gamestalker]

Just a quick glance on Hodgdon's site doesn't show IMR-4350, H is there, but no IMR. This doesn't mean that there isn't some IMR-4350 data published some where, but if not this could be causing a pressure issue? IMR-4350 and H-4350 are not the same powder.

The other element was oal, which you said is SAAMI max. Have you determined if they are seated up close too, or in fact touching the lands? This to could be creating a pressure issue.

If you can post pics with a full view of the case heads on the split necks, that may contribute to the pressure diagnosis also.

GS

 

[Crowman]

I'm using DuPont IMR reloading data. Got about a dozen reloading manuals, from the bullet and powder manufacturers. Loaded cartridges are not touching rifling. Cases are extracting easily. Tolerance on COL is +0.000/-0.005".

Aneal case necks? Never had to do this before. I never load to absolute max, also seat bullets a little shy. What temp to aneal at?

 

[RPRNY]

The powder question is important. Using DuPont IMR 4350 data is fine if you are using DuPont IMR 4350 powder, but it's been a while since DuPont owned or made IMR powders. Hodgdon currently owns the IMR powders and several years ago consolidated. If using H4350 use specific H4350 data. If using post DuPont IMR4350, use the correct data.

Clearly you know what you're doing so we're not suggesting you're making some stupid mistake but either you have a pressure problem, explicable only with load data error if bullets are seated not to load into the lands, or a brass problem, which is very hard to understand with some of it first time factory issue.

I think it's probably a dangerous/faulty chamber in the M95. In the interests of safety, you should send it to me and I'll dispose of it for you. ;-)

 

[gamestalker]

The part about cases splitting in both rifles can really only indicate that either both rifles have a problem, or the reloads have a problem, or the factory ammunition has a problem. It would be very unlikely that multiple coincidences, rifles, reloads, new brass problem, once fired brass problem, and bad factory ammunition would occur at the same time, if I'm clearly understanding the circumstances, that is.

So, are you saying both the new brass, factory cartridges, and the once fired brass were splitting?

And that this was happening in both rifles?

And the projectiles were seated from .000" to .005" off the lands?

And that the data is current for use with IMR-4350 and that cartridge?

I'll reiterate what I said above, that when up close to the lands, pressures will increase and can spike, quite high in fact. And .000" to .005" off the lands is in that range that pressures will rise.

I located some old data that shows a charge for 200 gr. Spitzer's at 42.0 - 44.0, but it doesn't have a bullet of 220 grs., but I'm pretty sure some data exists.

Way to many variables to establish a cause at this point.

GS

 

[Wil Terry]

Cartridges will split the case necks ONLY when they have the room to do so in the neck of the chamber. NOW that they've done it you can bet the ranch it is the brass' fault. The load NEVER has a thing to do with this. It could be a fault in the brass itself, it could be an induced fault from your loading dies, it could be they are just plain old and warn out even if they are all but brand new[ not uncommon]. ME....I'd bet the north 182000 acrers they are flatout too damned hard in the neck [ maybe all over ] and the chamber neck is Max-SAAMI spec at least.
YEP, annealing does work if it is done in time and done correctly.

 

[Crowman]

Case necks are splitting in both rifles. Load data is current for Hornady 220 grain round nose using IMR 4350, which is what I'm loading. Brass is either R-P or Winchester. Bullets are not in contact with rifling when chambered.

Found five of the cases. Lost the other two in the leaves. The factory loads were Winchester Super X brass, 180 grain, which I've had for a while. The two reloads were from a batch of R-P cases, 220 grain IMR 4350 loads. These were once fired brass and new.

The three cases to the left were Winchester Super X factory loads, and the two on the right were the hand loads. Splits were much more noticeable when hot just after firing. Less so now, after cooling.

Have no experience with annealing cases, never had to before. Not sure what to look for. What are the temp specs?

 

[gamestalker]

.000" to .005" is considered close, actually very close to the lands and will cause pressures to rise considerably. But again, this would only apply to the reloads, not the factory loads. So it's not likely the cause, simply because factory ammunition is also involved here, therefore the factory loads would have been seated to a depth that would accommodate most any SAAMI spec chamber.

Powder charge checks out as being in line with the components. But again, this would not be the cause as this problem is presenting with factory ammunition, as well as reloads.

Even though two different rifles are involved, this seems the most likely of possible culprits, though awfully coincidental. But again, a qualified gun smith has inspected and deemed the firearms as being in safe and sound condition. But I have to admit, the only real constant here, and the one possible culprit that carries the least number of possible coincidences, seems to be the rifles. If it were me, I would have both chambers re-checked by another smith. It wouldn't be the first time I've had a smith mis diagnose, or other wise make a mistake, stranger things have happened. Something I noticed while looking at those pics, the splits looked similar to what either high pressures produce, or, an out of spec chamber. And two of those splits look to be very characteristically similar, almost identical in shape and location.

I simply don't see how annealing can solve this if it's happening with new brass, once fired brass, and factory loaded ammunition. I sure wouldn't anneal necks on loaded ammunition, and doing so with factory ammo is very dangerous, and unheard of, so far as I know.

I truly hope you can identify the cause, but unfortunately this remains a mystery. But based on the many variables present, I would say with confidence, it may take further incidents and observation to shed some much needed light on this matter. Wouldn't it be nice if when these type of incidents happen, that only one single variable would be at play, rather than 5 or 6 different possibles?

Be careful, observant, and who knows what you'll discover with additional testing.

GS

 

[Edarnold]

Manufacturers only run low-demand brass when stocks run out, so for your 30-40 the 'new' ammunition might have been made ten years ago. Despite the head stamps, there's no telling who actually made those cases, might have been Norma or another European maker who have different standards for case hardness. Anyway, your split necks definitely point to annealing as a necessity.

 

[joed]

Back around 2002 I went through a similar thing. In 1980 I purchased 10 boxes of new Winchester .25-06 brass. I used 5 of the boxes and reloaded them till it was time to throw them away.

The last of the boxes I loaded but didn't use till 2002 when I started using the rifle again. Amazingly out of 60 rounds probably 10 split. It wasn't till I started to resize that I threw the brass away. When i pulled those cases out of the sizing die probably 50% of the necks cracked.

I was concerned that something was wrong with the rifle but I never had the problem again.

 

[Crowman]

Good info.

As stated in 1st post, the Krag was recently checked out by a gunsmith. Had front sight replaced, barrel recrowned, action checked and test fired. Passed a-ok. Also have shot rounds through it with no splitting in past. The 1895 is virtually new. Don't believe rifles are problem.

Reloaded cartridges are loaded to SAAMI specs....COL held to shorter side of maximum approved length, so they are not into the rifling. I use a Mitutoyo dial caliper to verify overall lengths of the finished cartridges and have micrometer standards to verify calibration. Also compared to the Winchester factory loads...all in spec.

Old brass now sounds likely on the factory loads...were not recent manufacture, I don't think.....judging from the boxes. Still had cardboard separators rather than styrofoam.

Would like to explore annealing as a cure. Any tips on how to do it without wrecking the case heads?

 

[homatok]

Here is one way (the one I use)

Annealing case necks by dipping them into molten lead that is held at about seven hundred degrees ‘F’ works well. Wheel weight alloy, which is approximately eighty nine parts lead, one part tin and ten parts antimony, melts at six hundred and nineteen degrees ‘F’ so you can safely set your lead alloy temperature at seven hundred degrees ‘F’. The use of a thermometer will take any guesswork out of the process. The reason for using lead for annealing is to keep the temperature low enough for proper uniform annealing, and that is simply not possible using the torch method. With a torch the case is often heated on one side more than the other, temperatures are not readily repeatable from case to case, and in falling over into the water, one side is quenched before the other.

To minimize the likelihood of lead ‘soldering’ itself to the brass case it is best to use as close to pure lead as possible (although any lead alloy will work). Anneal your cases with the fired primers left in, as that forms an airlock that keeps lead away from the inside of the case. With respect to annealing cases using molten lead, basically you: set the thermostat on your pot at seven hundred to eight hundred degrees ‘F’ pick up each case by the head and dip the neck of the cases about a quarter-inch into some powdered graphite or light oil (vegetable oil is fine). The oil keeps lead from sticking to the brass but, any lead that does stick is easily removed by a quick twist in steel wool while the case is still hot. Shake off any excess oil, dip the neck, shoulder, and about a quarter-inch of the case body into the molten lead and just as you begin to feel an uncomfortable degree of heat in your finger tips, drop the case into water. If you hold the cases in some other way than with your bare fingers, leave them in the molten lead from eight to twelve, but not more than fifteen seconds. When the case is hot enough that the lead does not cling to it, it is annealed. Pull the case up out of the lead, tap on the side of the case to remove any bits of lead (if the lead is really sticking, the case isn't annealed!), then drop it mouth down (straight) into a container that is mostly full of ice water. Following the anneal, it would be wise to closely inspect the inside of the case both visually and with a bent paper clip just to make sure there are no lead drippings adhering to the inside the case.

If you are left-handed, have the cases on the right side, the lead in the middle, and the ice water on the left. The cases go only one direction, to the left, and you use only one hand. If you are right handed, reverse the set-up. Because it only takes a few seconds per case, you can anneal hundreds of cases in an hour with this method. After the annealing process, remove the cases from the water, shake them out and use a piece of bronze wool to clean the annealed portion. This removes any residual lead and/or burned oil. Then, dry and tumble the cases to remove any traces of residual oil and they are ready to process.

One question--- is there any chance your cases have been exposed to Ammonia? Ammonia, in sufficient amounts can cause failure in brass.

 

[Crowman]

Homatok, Thanks for the procedure details.

As for ammonia contact,

The reloads, no. I keep ammonia products well away from my reloading shack.

I can't guarantee how the gun shop stored the factory loads before I bought them.

 

[joed]

The lead method for anealing sounds like more trouble than it's worth. The most common method is to stand the cartridges in a pan of about 3/4" water, heat the neck till it turns red and tip it into the water.