Cracked Casings - Please help!!!

[rjs5244]

I just started reloading and I am obviously doing something wrong and need help. I am shooting a Remington 700 30-06 using once fired (from factory loads) Remington brass. All of the brass was fired from this rifle. I am using CCI #200 primers and Nosler 165 gn ballistic tip. I am neck sizing using the Lee ultimate die set. I trimmed all the casings (although none of them actually needed it). The brass was tumbled and deburred. I didn't use a polish in my walnut shell media so there were still burn marks on the brass and someone suggested that I try steel wool to take it off. I put the brass on a drill and further polished with the steel wool. I seated all the rounds to an OAL of 3.320.

For my first 5 shots I used 49 gn of IMR 4064 and crimped. These shots were successful. I then increased the load to 49.5 gn and crimped. The first shot made a wrinkle on the casing that I didn't notice until later. The second shot split the casing (see picture) which sent powder and casing shrapnel back to me and fried my extractor. The split only goes around 50% of the casing. The shot was much louder and the gun almost jumped out of my hand. The point of impact was 5" lower than the previous shot. I replaced the extractor and took my rifle and casings to a gunsmith (and a few other people) and they suggested the powder was too hot, switch to IMR 4350, and don't crimp. The gunsmith also checked my chamber with go/no-go gauges (it passed).



I took their advice and then loaded 54 gn of IMR 4350 and no crimp. The first shot was successful and didn't wrinkle the casing. The second shot cracked exactly the same as the other although this time it did not fry the extractor and I took shrapnel in knuckle of my thumb and cheek.



Any thoughts? I'm obviously not going to hand shoot this rifle again until I feel confident that this issue has been determined. Thank you in advance!

 

[ReloaderFred]

You're suffering from incipient case head separation, which is caused by excessively setting the shoulder back when you size the case. When the shoulder is set back too far, it makes the case stretch when fired, and that stretching results in the brass separating at the junction of the case web and the case wall.

You should only be setting the shoulder back about .002" when you neck size the brass.

Hope this helps.

Fred

 

[The Bushmaster]

Once fired brass? Head separation? Check that you aren't setting the shoulder back. It looks like the case is gripping the chamber and the case head is moving back against the bolt face separating from the case. Just too much head space.

 

[The Bushmaster]

Damn Fred...Like minds....

 

[ReloaderFred]

Yep, Mike. And I know you weren't looking over my shoulder, since you're a couple thousand miles east of me..........

Fred

 

[Tony k]

So if op is neck sizing, the shoulder shouldn't be set back at all, right?

What about the crimping? I wouldn't crimp a 3006.

 

[rjs5244]

Thank you for the replies, I have no idea if the shoulders were being pushed back. I will run a few and check.

A few people told me not to crimp so I didn't on the second round and still had the second casing split on me.

 

[CZ9shooter]

So if op is neck sizing, the shoulder shouldn't be set back at all, right?

I agree. The Lee neck sizing die should have virtually no effect on the shoulder.

 

[ReloaderFred]

Crimping has nothing to do with incipient case head separation, and military ammunition in .30-06 has been crimped since 1906. "Neck sizing" can set the shoulders back, and in this case most likely is. If it wasn't, the cases wouldn't be failing.

Hope this helps.

Fred

 

[Tony k]

Crimping has nothing to do with incipient case head separation, and military ammunition in .30-06 has been crimped since 1906. "Neck sizing" can set the shoulders back, and in this case most likely is. If it wasn't, the cases wouldn't be failing.

Hope this helps.

Fred

And the problem didn't go away when he stopped crimping

 

[Nature Boy]

Without a case gage or a head space comparator, how would he know how far he’s setting the shoulder back?

I know folks say these tools are nice to haves but not need to haves, but I wouldn’t reload without them.

 

[greyling22]

If the op is using the Lee collet neck die on his fire formed for that rifle brass, not onlY is he not setting the shoulder back, the shoulder should be about as far forward as it can go. And if the chamber is within spec (it passed the go nogo gauges right?) Then perhaps the Remington brass is bad?

 

[mdi]

Isn't the Lee neck sizing die a collet die? If so it would have no effect on the shoulder. Factory ammo OK?

 

[jaguarxk120]

Borrow a set of regular dies (RCBS, Lyman, or Redding) and load your shells with those dies.

 

[Jim Watson]

Your loads aren't bad, although they do not follow the -10% starting load convention. 49.5 gr of 4064 is only half a grain below Nosler's maximum, but 54 gr of 4350 is 3 grains below maximum.
Your primers don't look bad.
The Lee (collet) neck size die does not set back the shoulder of the case.

I would not use that brass any more. Try a different brand.

 

[IMtheNRA]

I'd check the scale to make sure it is accurate. If you have access to another scale, see if they agree with each other. The fact that your second shot was much louder and the rifle "jumped" would lead me to check for a huge overcharge.

Another thing to check is whether or not this Nosler bullet has an unusually long base to ogive measurement. If it does, you may be jamming it into the rifling, which would cause higher than expected pressure.

 

[243winxb]

Measure head to datum of a factory round before firing.
Measure the same brass after firing.. whats the difference?

If head clearance of the factory ammo is excessive, brass can be damaged on the first firing. On the next firing, it separates. Some may come apart on FL sizing.

If pressure was high, the case head should show a raised ejector mark. I didn't see any in the photos.

 

[Sunray]

"...didn't use a polish in my walnut shell media..." That doesn't matter, you don't need polish. The brass needs to be clean, not shiney.
49 grains of IMR 4064 is the start load for a 165. 54 grains of IMR4350 is No$ler's start load too. 3 grains under minimum according to Hodgdon.
"...passed the go/no-go gauges..." Headspace(that isn't checking the chamber. It checks the distance from the bolt face to the 'datum' spot in the chamber.) is one thing to check. Isn't likely in a commercial hunting rifle, but it's possible. It's also easy and relatively inexpensive to have done. Wouldn't buy headspace gauges to do it myself for a one time thing. They run about $30 each or $58 for a Go/No-Go set from Brownell's.
Whole thing is way more likely to be the brass. Even though it's 'once fired', assuming by the OP. As mentioned, what's it doing with new factory ammo? The 'Paper Clip Test' being your friend.
http://bulletin.accurateshooter.com/2013/01/case-head-separation-causes-and-how-to-spot-problems/
"...case head separation, which is caused by excessively setting the shoulder back..." Nonsense. Case head separation is caused by bad brass or excessive headspace. Unless you're trying to sell useless digital headspace gauges. Cartridges do not have headspace.

 

[ReloaderFred]

"...case head separation, which is caused by excessively setting the shoulder back..." Nonsense. Case head separation is caused by bad brass or excessive headspace. Unless you're trying to sell useless digital headspace gauges. Cartridges do not have headspace.[/QUOTE]

Contrary to what Sunray posts, excessive headspace can be induced by setting the shoulder back too far when sizing brass. This has been proven over and over again. When the case expands once again to fill the chamber, the brass is pulled forward. It gives up at the point where the case wall and the base of the case join, hence "incipient case head separation".

Do as 243winxb suggests to find out how much the cases are expanding/stretching.

Hope this helps.

Fred

 

[Slamfire]

I am of the opinion that you sized your cases excessive. The base to shoulder distance of the case "cartridge headspace" was much smaller than the bolt face to shoulder distance on this diagram. The location titled "headspace gage".



Without cartridge headspace gages you have no idea how far back you are setting your shoulder. This problem is very common, reloaders oversizing their cases and setting the shoulders too far back, and reloaders affected post pictures all the time.



Before loading any more cases get a cartridge headspace gage and find out by how much you are pushing back the shoulders of your case after you size the case. These are two examples I use, the Sheridan case gage is a minimum chamber, which will tell you if your case is too fat, as well as being too long. The Wilson is cut large between the shoulders and the base but works fine for setting up dies for base to shoulder dimensions.



The problem for your current cases is that there are a number of known unknowns: One of which is how old are these cases and how long were they sitting around as factory ammunition?

If the ammunition was decades old before you fired them, it is very likely that gunpowder outgassing has embrittled the brass and your cases are unsafe for future use. If however the factory ammunition was shot within, lets say, ten years of production, you still have the problem that you over sized your brass. That can be fixed without losing anymore cases to case stretch. Let me discuss some theory: when a dry case is fired in a dry chamber the case neck and case shoulder adhere to the chamber walls. As pressures build, the case sidewalls have to stretch to allow the base to plant itself on the bolt face. If there is excessive stretch distance, the case will rupture. This is what happened to the 300 WSM cases.

Now, if you apply a light coat of a lubricant to your cases, like sizing lube, a grease, or something like this hair gel which is a combination of beeswax and vasoline. The case shoulders and case neck won't be able to grab the chamber walls. What will happen is as pressures rise, the case will slide to the bolt face without any sidewall stretch. The case will sit on the bolt face, the case shoulders will fold out, and you will have a stress free, perfectly fireformed case.

I have been doing this for years. The chamber in my 30-30 Marlin is huge, the base to shoulder distance is such, that had I not lubricated these new cases, I likely would have experienced case head separations in a couple of firings, if not the first firing.





I regularly grease my cases, particularly expensive $2.00 a pop cases like these 300 H&H Magnum cases. The base to shoulder distance is not controlled between cases and belt magnum chambers. Many shooters experience case head separations because their cases are too short for their chambers. I don't have that problem as on the first firing, I am lubing these cases and after firing, they are a perfect, stress free fit to the chamber of my rifle.

300 H&H Magnum







They shoot well too:





Shot this group this week

 

[Slamfire]

Contrary to what Sunray posts, excessive headspace can be induced by setting the shoulder back too far when sizing brass. This has been proven over and over again. When the case expands once again to fill the chamber, the brass is pulled forward. It gives up at the point where the case wall and the base of the case join, hence "incipient case head separation".

Sunray is channeling a particular attention seeking narcissist "Goofey Dick" . Goofey Dick is particularly upset that Wilson calls their gages "cartridge headspace gages" and Goofey Dick is correct that SAAMI does not have a term "cartridge case headspace". Goofey has found an itch he can scratch and sing of his greatness in measuring everything. Without the term cartridge headspace, Goofey has to create long, pedantic work a arounds to explain what could be explained with a concise term.

There is no law that says SAAMI owns the dictionary, no prison terms for creating useful terms and definitions, and the term cartridge headspace is easy to understand, so SAAMI and Goofey Dick can get in a canoe together and float down the creek, over the falls, to the benefit of us all.

 

[rjs5244]

Thank you everyone for the great advice. I will have my scale double checked. I have used the paper clip and did not feel anything inside. The gunsmith I went to used an angled pic and he could not feel anything either. I will cut a few cases to see if there is anything visual on the inside. Before I start shooting again, I will get a headspace gauge to verify.

 

[Orcon]

I work a guy who did this same thing on the second firing to about 40 nosler cases in a 300 wsm he was loading for a friend. I asked him to bring me a few once fired and a few resized cases. The difference averaged .019" on five cases. How the hell you set a shoulder that far back without bottoming out the die? This was done with Redding dies.

You really need a way to measure the amount you are moving that shoulder.

 

[Walkalong]

If it isn't incipient case head separation (See link below), it's bad brass.

https://www.thehighroad.org/index.php?threads/incipient-case-head-separation.734058/

Get some new brass, fire it again in your rifle, then measure where the shoulder is in comparison to the case head. You can use headspace gauges like Slamfire shows in his posts, or there are other ways as well, but you need to know where you are starting from so you can tell if the shoulders get moved back too much.

Read the thread on case head separation I linked to.

You really need a way to measure the amount you are moving that shoulder.

Yep.

 

[Walkalong]

"...case head separation, which is caused by excessively setting the shoulder back..." Nonsense. Case head separation is caused by bad brass or excessive headspace. Unless you're trying to sell useless digital headspace gauges. Cartridges do not have headspace.

No, that's nonsense, case head separation can most assuredly be caused from over sizing brass for use in a perfectly good chamber with no mechanical headspace problems. I sometimes call it "artificial" headspace (For which I get chastised by fguffey) because it does the same thing, it creates to much "head clearance", allowing the case to stretch in the area your brass separated in. Too much front to back slop when the cartridge is chambered. Whether it is from mechanical headspace being too large, or over sizing (Moving the shoulder back too far) the case for a perfectly good chamber, it all amounts to excess head clearance (front to back slop) when the round is chambered, allowing the case to stretch.

I do a reasonable job of explaining this in the thread I linked to.