30-30 neck splitting

[atr]

I was at the range the other day with a friend, helping him sight in an older 30-30 Model94. He was using brand new Remington CorLok cartridges. On 50% of the 20 rounds he fired half had neck splitting.
The splitting did not start at the lip of the cartridge but slightly down from the lip and extending about to the shoulder. I suggested an oversized chamber might be the cause. Was I right or did I miss other possibility?
thanks
atr

[Delkal]

Did the fired cases have the shoulder in the same position? The chamber could have been converted to the 30-30 Ackley improved.

But this doesn't explain the split neck. To make a 30-30AI you just fireform a standard 30-30 and it blows out the case and shoulder. But very few will split so with 50% failures my guess is bad brass.

[racepres]

32 Winchester vs 30-30

[littlejack]

Years ago, I had two boxes of Selleir & Bellot (SP) 7.62x54. I brought one box to the range to play with. Foolish me, I didn't check out the cartridges before firing, or after, (Factory ammo, got to be good, RIGHT???). So, got back home, and a while later, decided to prep the cases for reloading. Low and behold, there were multiple cases split from the top of the case to the shoulder. Note: I had never had any split brass prior to that with either reloads or factory ammunition, so the chamber was right. I dumped out the second box of factory ammunition (unfired). Some of those rounds were split. So, I dumped all that ammo and fired brass, and haven't used any Sellier and Bellot ammunition since.
It happens.

[Bazoo]

One possibility is that it's just a bad batch of brass.

[35 Rem]

I would guess the problem being that particular batch of brass. Hard to believe a factory chamber could be oversized enough to commonly split any brass fired in it.

[challenger_i]

I have encountered case splitting with S&B ammo in three different calibers: I will not be buying any more S&B!

As to Remington brass splitting, since the plant got up and operating after the last financial unpleasantness, I and a couple of shooting buddies have encountered case splitting on newly manufactured ammunition. While the factory made good on the defective ammo, it IS a bit disconcerting to have that common a failure rate.

Years ago, I had two boxes of Selleir & Bellot (SP) 7.62x54. I brought one box to the range to play with. Foolish me, I didn't check out the cartridges before firing, or after, (Factory ammo, got to be good, RIGHT???). So, got back home, and a while later, decided to prep the cases for reloading. Low and behold, there were multiple cases split from the top of the case to the shoulder. Note: I had never had any split brass prior to that with either reloads or factory ammunition, so the chamber was right. I dumped out the second box of factory ammunition (unfired). Some of those rounds were split. So, I dumped all that ammo and fired brass, and haven't used any Sellier and Bellot ammunition since.
It happens.

[Bloodman14]

Out of a new box of 20 Federal brand ammo in .303 British, I had 5 with split necks on the first firing. Sent them to Federal with a general inquiry; received a coupon towards a new box. Bad brass? Likely.

[challenger_i]

I have not experienced any splitting of Federal brass, but have encountered terribly SOFT Federal cases. To the point I avoid Federal, period.

[turtlezx]

old ammo ??

[Winger Ed.]

The factory's annealing process probably wasn't adjusted right on that run.

In modern manufacturing, if something isn't right, you don't make a thousand mistakes---
you make one mistake a thousand times.

[Hannibal]

As mentioned above, I'd first verify the caliber/chambering. Particularly if this is the first firing after a long period.

Things get forgotten. Possible it's not actually a 30-30.

Second question after verification would be has this ever been a problem before?

Depending on the answer the problem is probably that particular batch of ammunition. Try a completely different brand. Bad batches are rare, but it does happen.

[country gent]

I would definitely recommend a chamber cast of the rifle, This will show the chamber size and actual caliber any wear in the chamber. If another known rifle in 30-30 is available try a few rounds in it. See if the problem follows the rifles. The other would be to buy a box of 30-30 of a different maker or lot number and try that. If its 50% 2-4 rounds should show it. If the new ammo does this then its probably the rifle.

Also contact remington with the lot number from the ammo and inquire. But you will need the lot number at the least better is to have where purchased, when, and such.

[MT Gianni]

Size the brass and feel how much force it needs to resize it. Go over the base and neck with a good set of calipers, measure with a mike and write it all down, just use the calipers as a feeler. If as you said only 50% of the rounds fired split I doubt it is a bad chamber, probably bad brass. At 30-30 pressures, the brass should conform to the chamber. If the chamber is out enough to cause splitting, the cases will show you where it is off, especially the non split ones.

[stubshaft]

I chalk it up to old/bad brass.

[racepres]

!!! Calling atr !!!
Inquiring Minds want to Know Please....

[HWooldridge]

I was at the range the other day with a friend, helping him sight in an older 30-30 Model94. He was using brand new Remington CorLok cartridges. On 50% of the 20 rounds he fired half had neck splitting.
The splitting did not start at the lip of the cartridge but slightly down from the lip and extending about to the shoulder. I suggested an oversized chamber might be the cause. Was I right or did I miss other possibility?
thanks
atr

You mentioned "older 30-30". How old?

It's possible the chamber has expanded or worn - I had an 1889 Marlin in 32-20 that appeared to be in very good shape for its age, but every case split when fired. For whatever reason, the chamber was big enough that I could not save cases for reloading, so I sold the rifle. This was many years ago when the older guns were relatively cheap and easy to find but hard to repair - I thought it was a better choice to sell off at the time. However, it shot quite well and was handy to carry so it was a difficult decision that I have since regretted.

[Maven]

What stubshaft said! E.g., years ago I was given new WWII surplus loaded rounds for my .30-06 (WCC '45). After pulling and reloading with CB's and IMR 4198, half of the cartridges split at the neck. After I annealed them, that problem disappeared. Ergo, it pays to pull down all brass older than ~20yrs., anneal it, then reassemble it.

[725]

A friend's .450 Marlin split with factory ammo. Never figured why. It wasn't very old ammo.

[Gtek]

It could be several things and unless a deep dive with mic's and gauges? 30WCF ain't cheap no more but it still is about the least expensive out there. I would go buy a box snf mske some noise and see what happens with it.