Case head separation.

[Cdub338]

Have you tried a different box of brass or are you using the one box of recycled factory brass? Have you used a modified case with COL gauge to check the jump to the lands, maybe compare it to the factory ogive jump. By the case neck it looks like a little over pressure by blow-back, could be too close to lands?

 

[sendero21]

So I just got my 300 prc built a few weeks ago and have been shooting factory hornady match 225s. I wasn't getting the accuracy I wanted so I got a die and started doing some work up. I found a load my gun really liked at 79 grains of retumbo I set oal to the same as the factory stuff. Shot a 3 shot at .20 on center. However when I loaded it a second time testing the speed I got a case head separation. The brass has only been good for 2 firings. Just wondering if anyone has had any issues like this. Maybe a bad batch of brass?

Hi,
Get a set of Redding Competition Shell holders, follow the instructions which allow you to full length resize to the headspace dimension for your chamber. In other words sizing to the minimum, where the bolt just closes on the round.Thereby when so sized the brass can only stretch so far forward, as it's sized to fit the Chamber snug.
My uncle fired a Factory S&B 30/06 and suffered a full case Separation. It wreaked the Extractor on a T3 Rifle, he was very lucky indeed.
Best of luck with the project.

 

[SFC TONYM]

What is the little square piece of card board sent with the RCBS dies used for if not to start setting the dies for full length sizing ?

 

[JAYgs8163]

I just had the same thing happen 2 days ago with 1x fired factory loaded Hornady 7mag cases. I thought it was my load as well. I then went and bought a box of their factory ammo with 162 EldX. If I looked close I could see the beginning of it on the brass. After I resized the brass I loaded and had complete case separation. Looked identical to yours. I have not had a chance to dig further into yet but I had planned on calling hornady in the near future.

 

[T3ninja]

I hope someone starts making it soon.

Doesn't gunwerks make brass for it ??

 

[DJ Fergus]

I'm gonna guess that you're got alot head space. If that is true, FL resizing back to Sammi everytime will do this. My 25-06 had .010 more head space than Sammi max. It also done this until Remington made it right. They fixed it no questions asked & fast turnaround.

 

[normyt]

I had same thing happening on my 280 Rem when I first started reloading. I was FL sizing every case, even fire formed cases. RCBS die set as per instructions. This causes over working brass & excessive headspace especially on an already loose chamber.
What I done since is check every case with paper clip for groove on inside of case near head (incipient head separation). I then just bring ram up to die then back off die 1/2 to full turn. Then resize fire formed brass (which is usually initially tight to close bolt) by slowly turning die back down 1/8th turn. trying to bump shoulder .002-.003.
Seems to have solved problem so far.

 

[hoffbill]

A lot of good suggestions have been posted on this but as with any troubleshooting process if you do not start at the beginning and use a logical process of elimination you can end up chasing your tail. The first step is to confirm that the rifle is head spaced correctly. Many of the suggestions seem to be aimed at creating custom brass which may be sized out of tolerance and specs in order to fit a chamber with excessive head space. Using fired and unfired brass to measure and set head space on a rifle is a no-no. Buy a go no-go guage set for the caliber or have a good gunsmith check it because if incorrect head space is the issue, all the customizing brass and hybrid die settings are unnecessary.

 

[greenejc]

So I just got my 300 prc built a few weeks ago and have been shooting factory hornady match 225s. I wasn't getting the accuracy I wanted so I got a die and started doing some work up. I found a load my gun really liked at 79 grains of retumbo I set oal to the same as the factory stuff. Shot a 3 shot at .20 on center. However when I loaded it a second time testing the speed I got a case head separation. The brass has only been good for 2 firings. Just wondering if anyone has had any issues like this. Maybe a bad batch of brass?

Well, first, according to Hodgden's on-line manual, you're about 2.5 grains over the max load. So pressures are probably exceeding SAAMI maximums. Second, case head separation with the second shot is an indication of either an over size chamber, excessive headspace or both. Have a different gunsmith check your chamber. Don't fire it until the chamber has had a cast done of it and been measured for size and dimensions/headspace. Also, drop your loads down to under 76 grains with Retumbo. Hodgdens lists the 220 grain ELD-X as having a max load of 76.4 grains with this powder.

 

[Hawk in WY]

Deleted.

 

[sable tireur]

Doesn't gunwerks make brass for it ??

Gunwerks doesn't make brass of any sort at all. They have Atlas/ADG make all the brass for them private labeled with the Gunwerks name on it. You won't get the pretty little 50 count boxes. Instead you get a zippered soft case labeled Gunwerks.

 

[antelopedundee]

Sounds like you have excessive headspace. Have a gunsmith or the rifle manufacturer correct it.

Or you could partially pull the bullets and re-seat them until they lightly jam into the rifling. After firing the cases will now be fire formed to fit the chamber. When resizing set your die such that the resized cases will chamber with just a smidgen of effort.

 

[Truc]

Only way to set a die is to fire form a case, preferably hot then resize the case with die well away from the shell holder. Then check to see if your bolt closes without the firing pin and with just a touch of force to close. If it drops then either load wasn't hot enough to warrant resizing or you oversized meaning raise the die some.

 

[DaleJ]

Adjust dies for your chamber. Expand neck one caliber bigger. Return FL sizing die to press, remove firing mechanism from bolt on rifle. Adjust FL sizing die down incrementally until you feel just a slight nudge closing bolt. I never trust die manufacturers measurements, this works for factory and custom wildcat chambers.