A good friend shot a Red Deer Stag with it, standing broadside, and from 50 or 60 yds. At the well aimed shot the deer stumbled almost imperceptibly as his son, who was beside him and lloking through the binos told him, because with the recoil he did not ntice, and then lifted his head and started looking around.
He reloaded and a second shot put the stag down.
The first bullet had sort of splashed itself against the skin, penetrated about half an inch and was visible from the outside.
The front core was properly expanded with the front core gone.
Looking at if from behind showed that the rear core was not there. Inside it was clinically clean like it had never had any lead inside, as lead normally would have left some traces. This lack of weigh and SD and the bullet instantly expanding to a large frontal surface could have caused the bullet not to penetrate, I guess.
Distance was short but I find it amusing that the bullet flew straight and hit the deer exactly where my friend was aiming, a shoulder shot that would have gone throgh both scapulas, exactly like the second bullet did.

Now looking at the photos I notice that the bullet does not present the crimp at the edge with which the Partitions lock the rear lead core.

If that were the case there is the possibility that it fell off during the bullet flight?

Was that a bullet he loaded or was it "factory ammo" that uses a Nosler bullet?

Why the hell would you use a obviously defective bullet in one of your reloads?

It was factory ammo, Nick.

I'd advise Nosler. At the very least they would replace the ammo with a voucher for new ammo.

Alvaro,

VERY interesting!

Like you, I suspect the bullet somehow missed getting the rear core crimped-in during manufacturing. Or it never received the rear core at all.

Have a number of recovered Partitions in my collection, up to 400-grain .416s, and have never seen anything like that.

Very interesting. It would be good to see what Nosler has to say about it.

Happily it was a red stag, not ole griz he was taking a poke at!

wouldnt it be dark inside where the core goes from powder burning if it didnt have it from the factory

I had this "failure" of a 300gr .375 NP years ago on a big moose. This bullet slipped its core after traversing 3'+ of meat and bone on a pretty hard quartering away shot. The first shot was broadside at about 75 yards, and he ran off. As I approached where I thought he was, all of a sudden a whole bunch of antlers suddenly rose up from the willows and tried to run off! The bullet traversed from about the last rib to the neck, where I found it lodged against the spine after shearing bone. I couldn't find the core, but I can't imagine it popping out early and the bullet penetrating that much. The first bullet (shown with the "failed" one resting on it) was found partially exited on the off side of the broadside shot. The shank of the bullet was sticking out of the hide, but the mushroom caught and prevented it from exiting completely.

The only other "failure" I've had with a Partition was another 300 grainer from the same .375 when I shot a charging brown bear at 2 yards as it was jumping up at me. The bullet entered at the junction of the neck and chest, messed up some vitals, and then literally pulped 5 or 6 inches of spine. The animal folded up like a book at the shot. All I could find of the bullet was a bunch of copper and lead particles, no discernable pieces at all. Maybe
the bullet didn't go to dust, but I couldn't find anything of it. Despite my notions of what constitutes perfect performance, that 300 grainer at 2550 kept me from getting rearranged that day.

If it really didn't have the front core it seems likely that, at the time of loading the magazine, the shooter would have noticed that it was missing. The lead tip, if the core is in place, is very obvious.

Thanks, John.

First time I have ever heard much less seen this happen!

It just proves that anything made by man can fail.

I am more in your second thought that maybe it never received the secon core. As Gene270 says (thank you!), maybe if it had been empty from the beginning there would have been some powder residue?

Alvaro

MickeyD,

We are talking it hadn't had the rear core.

Yes, if it had been the front one it would have been very obvious.

Alvaro

I don't know how Partitions are made, so anyone who knows please chime in. If the rear core is inserted into the rear of the copper jacket in solid form and crimped in (instead of molten/softened lead "poured" into the rear of the jacket), a lube might be used, and that would account for a lack of lead stuck to the jacket.

Without a crimp, the rear core would leave the barrel at the same velocity as the rest of the bullet and wouldn't be subject to air drag, so it would continue in its position with the rest of the bullet until impact. I wonder if upon impact, enough resistance, particularly if something relatively solid was hit (bone or thick muscle around bone), could cause enough force to be transmitted to the bullet that the rear core could slip out, particularly if a lube was involved and no crimp was applied. If the rear core immediately exited the rear of the jacket upon impact, a large portion of the bullet's momentum and energy would be lost.

However, I'm not sure the physics would work out because I would be surprised if the shoulder of a red deer would have enough resistance to stop a 0.308" Partition, even with a loose rear core.

Did the hunter search for the rear core on the ground around where initial impact occurred?

R R,

He didn´t because his first impression was that the rear core had retreated inside, as they often do when stopped inside an animal.

It was during a later inspection at home, when cleaning the hair and blood that he realized what had happened, and called me on the phone to tell me,

There's another physics problem: In a head on collision would an unrestrained passenger in the back seat go out the back window?

Nobody's suggesting the bullet didn't have the FRONT core before the shot. Instead we're debating whether it had the rear core.

Partitions sometimes lose all of the front core when they impact game.

I was thinking the same.

Noticing the turned cannelure, how old might this ammo have been? Not that it matters but I wonder if rear core security has evolved as well.

Keep us posted on this one - especially if Nosler has a comment.

The more analogous scenario would be a passenger in the back of a pickup truck that struck a large tree. Could the passenger bounce off the back of the pickup's cab? Motion of passenger at impact would be forward, but with sufficient resistance (force applied in stopping the truck) the body in the back could in essence bounce and reverse course.

Like I indicated in my original post, I would be surprised if even a large bone would provide enough resistance to a 30 cal Partition for an unrestrained rear core to reverse direction considering the impact velocity it had, but I'm not going to say it's impossible.

I wouldn't be surprised if someone at Nosler knows the answer to our physics problem. If they didn't, they could test the scenario today if they wanted to by simply not crimping the rear core of a Partition and firing it into test media. If 3 bullets prepared the same way yielded the same result, we'd have an answer.

From what I've seen if anything happens to rear cores in violent impacts it's not a bounce back. Rather the rear core is pressing forward so hard that the jacket bulges radially just behind the partition and the rear core material becomes a mushroom shaped plug stuck in there.

Mathman,
I have seen that bulge in Swift a-Frames, but I have necer seen it in Partitions.
Do you have any pictures you could please post?
Thank you.
Alvaro

I have noticed that some bullets bought as separate components do not have a cannelure, while the same bullets loaded in factory ammunition come with it. I have seen in in Nosler Partitions and Nosler E-Tips as well.

In this case it was a Federal loading. Caliber was 300 WSM and ammo was not old.

I have seen quite a few bullets tumble after they hit a big game animal, or in test media. Have recovered them with the mushroom facing "backwards" when the bullet was caught by the hide on the far side. On one of the weirdest occasions, a well-known "premium" .375 bullet apparently tumbled so violently after hitting a broadside Cape buffalo's shoulder bones that it spun through the lung BEHIND the shoulder, and was recovered from the ribcage on the same side of the bull it entered.

No personal pictures. It's just what I've found investigating and it probably was an A-Frame I'm remembering.

Wondering if it did NOT have the rear core when loaded....would the bullet have hit to point of aim? I would think it would have flown off course.

The lead rear core isn’t going to “bounce back” out of the rear of the jacket. It may get ripped from the rear of the jacket from deformation but lead doesn’t bounce too well. The inertia of the rear core will cause it to try to continue in its direction of travel on impact, sometimes bulging the jacket just behind the partition. You can see slight bulging just behind the partition in pabucktail’s photos.

I’ve never recovered a partition from a game animal but have found many of them after they hit a dirt backstop and the inertia of the core will have bulged the jacket behind the jacket.

My thoughts are that the rear core was never there and the front core was shed as Partition’s sometimes do.

The rear core may deform the jacket radially IF the rear core is crimped into place such that the amount of force required to overcome the crimp exceeds the amount of force required to deform the rear core/rear jacket. If the rear core is not crimped, the rear core could respond differently than it normally would because even a thin tube has considerable radial strength.

My guess is, it didn’t have the rear core to begin with. Give the number of bullets produced, absent 100% inspection, a mistake will occasionally make it through. Years ago, I found a Norma .44 Magnum factory load with the bullet seated backwards. Also consider that a bullet is a relatively small, marginally stabile object traveling through an uncontrolled environment, with infinite possible occurrences at an incredible speed...enough speed to provide adequate energy for all sorts of things to happen. Weird schit will happen.

Alvaro,

Did your friend notice any difference in recoil between the first and second shots?

I did some quick, rough estimates, and if the bullet was missing its rear core, the recoil probably would have been about 75% of what a normal round would have. I know I don't notice recoil as much when I'm shooting a deer as when I shoot paper, but 25% less recoil could be noticeable.

Assumptions/estimates:
165 grain Partition with rear core weighing 55 grains (33% of total bullet weight)
H414 66.9 grain powder load launching 165 grain bullet at 3100 ft/sec and 110 grain bullet at 3330 ft/sec (Hornady 7th Edition)

If you look at the OP’s original pics you can see that the base crimp is still there and hasn’t been compromised. In addition there is no swelling of the jacket right behind the partition. Again, leads me to think the rear core was never present.

The Nosler partitions that I’ve recovered from dirt backstops usually show some expansion of the jacket just behind the rear jacket/core as the rear core slams into the partition which, in turn, swells the jacket right behind the partition.

L

I asked him that very same question and he told me he was very excited and concentrated on the stag and he did not notice any difference in recoil, nor noise nor anything. Ufortunately he did not keep the spent case, as it might has provided us with some information like some soothing in the neck-shoulder area, or a protuding and rounded primer ... I am thinking in signs of very low pressure due to reduced bullet weight




I don't think that the base crimp is there... On the other hand I have recovered a few Partitions from game, not too many because it is a bullet I don't shoot much, but a few, and none of them exhibit that bulging right behind the partition, so common in Swift A-Frames.

navlav8r,

This is one of the 150gr 7mm Partitions I recovered in one single cull hunt in Namibia from Oryx, Blue Wildebeest and Red Hartebeest. None stayed inside of anySpringboks or Warthogs I also killed.

The base crimp is quite obvious, as much as I can't see it in the empty Partion pictures.

The bulge that you mention, and that I have never seen in any Partition that I have recovered from game, is not there either. I do not mean it cannot happen, I only say I have never witnessed it in the 15 or 20 Partitions I have recovered from game.

Nice looking Partition you have there.

I don't think that the base crimp is there... On the other hand I have recovered a few Partitions from game, not too many because it is a bullet I don't shoot much, but a few, and none of them exhibit that bulging right behind the partition, so common in Swift A-Frames.
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The experiences you both mention point to the same thing - considerable force is required to bulge (radially expand) the rear core of a Partition. A dirt backstop exerts enough force (resistance) to quickly stop a bullet traveling over 2000 (perhaps close to 3000) feet per second. That violent deceleration exerts considerable force (F=ma) when compared to the forces the bullet is designed to overcome in an animal. The bones of most animals commonly hunted aren't going to provide even close to that level of resistance (force), as evidenced by the effectiveness of Partitions in penetrating almost any type of bone to get to the vitals and often exit the animal completely.

Navlav8r - Additionally, your experiences point to the typical Partition rear core crimp being VERY effective in retaining the rear core because that little crimp has to withstand enough force to translate force from along the axis of the bullet into the radial stresses that exceed the deformation point of the rear part of the jacket, which is a tube.

You probably are very familiar with this from your professional background, but I'm sure for others who are curious videos are readily available showing how much pressure two liter soda bottles can hold before bursting. There's a very good reason why pressure vessels (e.g., household propane tanks) are typically designed as cylinders with half spheres at either end - the ability of even a thin shelled cylinder or sphere to resist radial stresses without deformation.

Reminds me of the videos I saw in our driving class when I worked in Dubai...

Gotta love the not-yet-ignited powder kernals leaving an imprint on the exposed rear lead core. All my recovered partitions exhibit this.

Alvaro,

I have only rarely seen any bulge in the rear of the Partitions, and when it happens it's very slight--and usually caused by the bullet hitting major shoulder bone, like that on a Cape buffalo or similar-sized animal. The folks at Nosler tell me the rear of the jacket is carefully tapered to prevent such bulging near the partition, the result of much experimentation over the past 70-some years.

I've taken dozens of animals, deer and elk, with various caliber partitions and have never seen that before. I have only recovered four however with the front part of the partition partially smeared off, 60-70% retention. Curious regarding Nosler's impression.

So Chamois, you never stated what caliber the original partition was. It looks like it may be a medium bore.

I just looked a sample of three .338 Partitions I have on hand. All three samples (210, 250 Sptzr and 250 RN) have a square, non-crimped base. In addition a look at a .375 cal / 300 gr Partition shows no heel crimp. My .30 cal Partitions (except Partition Golds) have crimped bases like the one shown in the picture above. Maybe someone like JB knows the cutoff in caliber for crimped/non-crimped Partitions.

Edited: The thread title states .30 cal, so my medium bore theory is shot down.

I have recovered dozens and dozens of Partitions from deer, elk, and a moose, and I have never seen anything like that.

Obviously a defective bullet.

Was this a factory load or a handload?

JW

Not being smart. Earlier here he said it was a
Factory load.


Jerry

Didn't the original Partitions not have a crimp or not as obvious a one as the current bullets? Front core is pretty typical, back looks defective, no crimp or taper. There are many accounts of Noslers PT loosing one or both jackets but it usually is in association with encountering a signifigant amout of bone and usually tumbling severely. The PT are so good that people think there was some diabolic intervention when they fail, whereas all bullets can fail under certain conditions.

I can tell you that .35, 225 gr or 250 gr Noslers have square bases and are crimped to hold the rear cores but they don’t have that boat tailed look as shown in the OP. IIRC, Nosler .338 bullets have square bases too.

If the rear core wasn't there, first thought would be the impact would cause the partition to partially collapse into the empty space. Which didn't seem to happen..My guess....it was originally there...

I'm in the camp believing that the rear core was originally present. I'd be shocked if a partition missing the rear core would have flown true at 50/60 yards, plus, I suspect that a hollow rear section would have flared out like a skirt as it left the confines of the muzzle and while there was still remnants of pressure behind it.

bruinruin,

the very moment the bullet exits pressure instantly drops to atmospheric pressure so I would not expect any of thet flaring.


also, if the bullet had had the rear section filled with lead I cannot find and explanation for it splasing agains the hide and not penetrating.

for me it is a real mistery, but in my opinion the rear core was not there from the start.