338Edge - Remington Case Cracks and Split

[300rum]

Hi,

I need somebody with experience or somebody who got across this situation to confirm or guide me.
Today I was shooting my 338 edge, confirming drop chart and I got a strange situation.

From 50 rounds fired I got 3 cases splits and cracks on the base area.
I inspect very carefully every case prior reloading, without seeing any signs.
I run 92gr H1000 at 2744fps at 5329 elevation, and THIS LOAD IS NOT HOT.
THE HOT LOAD FOR MY RIFLE IS 93.5gr h1000 so I'm on the safety area.

This cases was reloaded 10-12 times, and trimed 3-4 times
No loose primer pocket, no hard lifting bolt, just sometimes hard extractind case.(this is the time when I trim the cases to the size)
I do FL resize.

As you see in the image around the base area I have light marks around base as a sandpaper marks around the case base.

The splits is because of too many reloading? or a problem with the chamber?

Any advise will be more then welcome!.

 

[700P]

The same thing happen to me with my 338LM I was bumping the shoulder to much, I started using Redding comp shell holder they come 5 in a set, I still full lenght size the case but I'm only bumping the shoulder .001 to .0015 , with the Redding shell holder I bump them on the bottom of the sizer die and now my problem gone.

 

[AJ Peacock]

+1 for what 700P said.

That is called case head seperation and is due to thinning in front of the web (the thick part of the case head). If you push the shoulder back too much, everytime you shoot a piece of brass, it stretches to fill the void and the stretching happens the most from that point and the brass flows forward. After enough shots, the brass gets so thin that it fails.

10-12 times is very good brass life. I've shot brass that much, but don't trust it. I throw my Edge brass out after 8 reloads.

Do you measure how much you're pusing your shoulder back? As 700P said, just push it back .001-.0015". You can measure this value with a bullet comparator.

AJ

 

[alf]

CJ,

When you set up your full length die, screw it out a turn or so, then bump the brass a bit at a time, screwing the die down till the bolt closes with a hint of resistance. Pull your firing pin assembly out of the bolt for the best feel. I tell guys if you can use your nose to push the bolt down, it's about right. That ends up at about 1 to 1 1/2 thou bump.

 

[300rum]

CJ,

When you set up your full length die, screw it out a turn or so, then bump the brass a bit at a time, screwing the die down till the bolt closes with a hint of resistance. Pull your firing pin assembly out of the bolt for the best feel. I tell guys if you can use your nose to push the bolt down, it's about right. That ends up at about 1 to 1 1/2 thou bump.

what bolt? rifle bolt or fl die press bar?
sorry to ask dump question.

at the die press, i have a question.
if you deprime/fl resize the case, when you press down the press bar, the case is almost inside the fl die, and the shell holder is touching / pressing the base of the fl die.
if i continued to pull down the press bar the case holder is retracting 1 mm back (i have a gap between case holder and the fl die base). in this position, the press is completed to the end movement.
so... base on this situation, when i have to unscrew back the fl die to do not push to much the case sholders?
1. at the moment when the case is full inside of the fl die, and the case holder is pressing on the fl die base?

 

[bigbuck]

+1 on what AJ said If you make it to 8 loads without split necks or other problems I say toss it after 8 loads ! 10 to 12 loads out of that round your lucky I've never been able to get that many loads out of my 300rum brass while I was loading on the hot side of the book. I say the only reason you made it this far is because as you mentioned your loads are not hot,just my opinion.

Bigbuck

 

[AJ Peacock]

what bolt? rifle bolt or fl die press bar?
sorry to ask dump question.

at the die press, i have a question.
if you deprime/fl resize the case, when you press down the press bar, the case is almost inside the fl die, and the shell holder is touching / pressing the base of the fl die.
if i continued to pull down the press bar the case holder is retracting 1 mm back (i have a gap between case holder and the fl die base). in this position, the press is completed to the end movement.
so... base on this situation, when i have to unscrew back the fl die to do not push to much the case sholders? CORRECT
1. at the moment when the case is full inside of the fl die, and the case holder is pressing on the fl die base? When adjusted correctly, the shell holder will probably NOT be touching the die.

He is talking about being able to easily close the bolt on your rifle. When adjusted for a slight shoulder bump, it is rare that the shell holder is touching the die.

AJ

 

[300rum]

thank you A.J. and thank you for All of you who light me up.

A.J. i will follow your advice step by step, and i will let you know.
for now... i will throw away all this batch of cases, just to be safe and start with a brand new set.

i will let you know how it works in few weeks.