Case head separation...223 caliber...

[Metal God]

The thickness of the case neck wall has little to do with how soft they are . It's the case makeup as a whole that is softer . I have some LC-14 cases right now that I can barely get past start/minimum charges before getting sticky bolts . The cases are just two soft and are stretching to much when fired and not retracting to allow easy extraction .

These are 308 cases that have a water volume of 54.9 avg that I can't load more then 41.5gr of IMR 4895 pushing 168gr Hornady BTHP at 2490 fps . Everything about that says I should be able to get at least 42.5gr and a velocity of 2600fps but there is no way that's happening .

Even though I have found an accurate 41gr load combo with that brass . I fully expect my primer pockets to loosen up rather quickly .

Does anyone think it's odd the OP got 12 firings by neck sizing and never had the FL size the cases . Also having head separation when only neck sizing . After the second firing the case should have nowhere to stretch causing the head separating . So that leads me to think they where fired 12 times and FL sized at least twice maybe three times .

Here are some PPu cases that where FL sized only 3 times



I ask the OP how many times did you FL size those cases ? Did you just bump the shoulder back or return them to SAAMI minimum ?

[Bill Steele]

Post #6

He said he F/L sized and trimmed them every 3-4 cycle.

[pacrat]

MG said

Does anyone think it's odd the OP got 12 firings by neck sizing and never had the FL size the cases . Also having head separation when only neck sizing . After the second firing the case should have nowhere to stretch causing the head separating . So that leads me to think they where fired 12 times and FL sized at least twice maybe three times .

MG, the OP said in post #6

I had 12 reloads on this case. I do keep track of that. All the other brass looked fine on the outside. I have not annealed any of these cases other then the original factory annealing. No problems with neck tension. I can get away with neck sizing about 3 to 4 times, then I full length size and trim.

So he FL sized 3-4 times depending on the count. Shoulder bump or full SAAMI remains to be determined.

OP, annealing will have ZERO effect on head seperations. Unless you drastically overcook them.

I also shoot a top break .223. It is a H&R SB-2 reciever with a bull barrel. But it only has about 100 rnds down range so far.

JM2c

[Metal God]

Sorry missed that , that's on me . I think it's likely he FL sized them down to much each time . As shown in my pic it only takes three to get to the center .

[McGuiver]

Case head separation...223 caliber...

I'm new to rifle reloading here. I was surprised to get 12 loads from this brass.

I full length resize with with my carbide Dillon 223 die. It also bumps the shoulder back into place. I know the case is stretching. I trim them to 1.745". By the time they get to 1.760 they need to be FL resized again. That is 0.015" of stretch. During that 0.015" of stretch I neck size only. I do notice that after 4 times of neck sizing the shoulder is to far out of spec. It is very difficult to close the action even if the brass is under 1.760".

I took one of my lock picks I use for work and modified it to check the inside of the brass. Out of 50 rounds I checked I found 2 more that will go to the scrap bin because of the inside ring.






I had to file down the pick a little to reach all the way to the back of the 223 brass.

This brass had been FL resized a total of 4 times.



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[Metal God]

What press , and shell holder do you use and how is your die adjusted ?

[McGuiver]

What press , and shell holder do you use and how is your die adjusted ?

I'm using an RCBS Rock Chucker for the press, Redding shell holder, and check the brass against a Dillon Case Gage in 223. Nothing fancy. The FL resizing die is a Dillon carbide die. The neck sizing die is a Redding die.


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[Metal God]

I looking more for does your die and shell holder make contact when the ram is fully up or did you screw the die all the way down until it bottomed out on the shell holder then locked it down ?

I think your other answer has answered the question though . You are likely bumping the shoulders back to much for your specific chamber causing to much head clearance ( some say excessive head space ) Even neck sizing after , the cases are still stretching because of the excess head space you created when you FL sized the case each time . If your chamber is on the long side of spec and you size your cases on the short side of spec . It will only take a few firings to get head separation .

Here's how you can use your gauge to determine how to and how much to bump your shoulders back

https://www.youtube.com/watch?v=RuJYpm-qplQ

[Metal God]

His case is a good example of a larger chamber since his fire formed cases are .008 over max . When he sized the case the first time his die and shell holder likely made hard contact which sized his case down to SAAMI minimum or .014 shorter then his fire formed cases . That would have created WAY to much head clearance and he would have got head separation in 3 sizings maybe even 2 . So he adjusted the die up ( unscrewed it 1/8 to 1/4 turn in his case ) to size the case less untill he only bumped the shoulder back .004 .

Do you understand what's being said ?

[liber]

The thickness of the case neck wall has little to do with how soft they are . It's the case makeup as a whole that is softer . I have some LC-14 cases right now that I can barely get past start/minimum charges before getting sticky bolts . The cases are just two soft and are stretching to much when fired and not retracting to allow easy extraction.

It seems that 223 cases get hotter than 308 for me, and they tend to get banged up more. I wasn't sure if having thicker brass would make them more durable or not, but that is what I was hoping.

Here are some PPu cases that where FL sized only 3 times

Damn, those are fugly...I saw PPU had a recall on 6.5 Grendel ammo recently.

[roostersgt]

Unless there's something special about the brass, like say 300 Savage, or some other unicorn caliber that's pricey, I toss after the 5 firing, regardless of what it looks like. .223 brass is pretty cheap and plentiful to be reloading it 12x, especially when milsurp stuff can be had for pennies. I think the metal just got too fatigued from heat and stretching after 12 loadings. I'm in wonderment as to why the primer pockets didn't get too loose before the case head separation occurred.

[Metal God]

It seems that 223 cases get hotter than 308 for me, and they tend to get banged up more. I wasn't sure if having thicker brass would make them more durable or not, but that is what I was hoping.

Yes assuming the case hardness is the same . The thicker necks in theory should be more durable and last longer .

I'm in wonderment as to why the primer pockets didn't get too loose before the case head separation occurred.

Because the case stretching back to the bolt face which is what causes head separation can happen at lower pressures then what will blow out primer pockets . The head is REALLY thick compared to the rest of the case . It's the very reason the case separates just above it . That head material is much stronger do to it's thickness . Pressure has to be way up or cases need to be softer like Fed cases for primer pockets to blow out/ enlarge .

[roostersgt]

Thanks, learn something new everyday here. Always thought the primer pockets got loose from the combination of firing and the removal/replacing of the primers.

[Metal God]

No problem . FWIW there are guys reporting 40 and 50 reloads on one set of brass . Now that's bolt gun bench rest guys but it appears possible so no , repeated seating of primers does not wear out primer pockets .

[tvfreakarms]

Couldn't annealing the brass will make it last longer?
After shooting the same brass 4 or 5 times before it needs to be annealed?

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