Whats going on with my 300

Hellpit

Hellpit

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:eek: Check these out..

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Old brass loaded too many times?, excessive head space?.. Any one experience this? Primers not popped, but flattened a bit. (The edges are not round anymore)

Out of a batch of 30 rounds, recently fired, 10 show stretching near the base, and 5 or 6 brass failures.. One actually broke in half as I pulled the bolt back, and ended the day of shooting. Man that was a ##### to get out of the chamber, had to build a special tool to pull it. This batch of brass is probably on the fourth reload.
 
I was told that kind of thing can be caused by very heavy loads or after being resized many times(5-6). Apparently if you aneal the brass before resizing after a few reloads it helps with the cracking. I am going on what I have been told by others so I urge others to correct me if I am wrong...strangely enough this issue actually came up today while talking to a friend.
 
If you full length resize this can happen. I would have expected a couple more resizings though. But many things can speed up the process. The size of your particular chamber, the amount of resizing your particular die does.

Neck sizing will extend the life of belted magnau brass, sometimes quite dramaticly.

Was the brass new when you started? What brand? What rifle?

More info please.:)
 
Looking back at the pics, I see all the damage to the case mouth as well. Annealing will help here.

Really curious on the make and age of the brass.
 
The brass in question came with the rifle, so I don't really know how many times it's been loaded, but I guess 4 or 5. (Twice by me)

Winchester Brass
180 Grn Nosler B-Tips
68 Grns IMR-4350
Sako 2 lug action - 24" Brl
Full Length Dies


I think you guys might have a point with the full length dies.. I'm gonna look around for some neck dies, and give them a whirl. Gonna have to look up info for anealing necks also. I think I might just toss the complete batch out, as well as the rest of the loaded rounds after they are fired, and go with new brass. Thanks for the tips.
 
The stress cracks near the base of the case have little to do with pressures. This is caused by resizing the brass slightly too short for the chamber. Each time the brass is FL sized the shoulder is pushed back a few thousandths of an inch. When it is fired, the force of the firing pin drives the loaded round into the chamber those few thou till the shoulder makes contact, and then the case sticks there from the internal pressure building within. The pressure now forces the head of the case back into contact with the bolthead, stretching the case exactly where you see those stressmarks, and partial head separations. Adjust your sizing die "out" to eliminate the shoulder movement on FL sizing, and this problem will disappear. I never discard brass due to separation issues, only due to cracked/split necks, which can be arrested by annealing the neck area only. Do get rid of all that lot of brass, it is finished! Regards, Eagleye.
 
Looks like the brass has been loaded too many times as well as full length sized and the load maybe too hot. Is your data within the load manual limits? Ditch the brass, go with new and make sure your load is not too hot. You might want to do neck sizing only. You can read how to do this in any manual - it's not hard to do. If cracks continue with new brass, take the gun to a gunsmith to check the head space and chamber.

Just a tip but I wouldn't trust brass that was handed down to me - one just doesn't know what the previous owner did with the load and how often the brass was reloaded.

Good luck.
 
With neck-sizing, I have sectioned a 300WM cases that shows no thinning after 12 reloads. But the primer pockets were starting to loosen up so I chucked them anyway.

I would venture the brass in the picture has been reloaded many times. Into the recycle bucket with it.
 
Would agree on above that too much resizing is probably culprit. I would not shoot the rest of that batch, pull the bullets and toss the brass. How much leakage at 60,000 PSI plus do you really want 6 inches from your head? You might get away with shooting the rest with no ill effects, or not.
 
That brass is done. When it starts loosing peices of the neck and splitting the neck it work hardened big time. Looking at the condition I'd just chuck it and get some new stuff. The splitting buy the belt is impropper die adjustment as Eagleye has said. I bet your accuracy takes a big step forward with new brass. Read a couple of loading manuals very carefully reguarding sizer adjustment with the new stuff.
 
Im at work right now, so I can't check.. I've got Hornady Full length and RCBS Full length dies. The case's in question had been sized with the hornady, I wasn't aware that they could be adjusted..? Are the RCBS dies adjustable? I'll have a closer look at them when I get home.
 
Adjusting a sizing die means to unscrew it a bit to raise the die. This will prevent the shoulders of the brass from being set back. This in turn will stop the brass from stretching and eventually separating when fired.

The best way to adjust the die is to unscrew it about 1-1/2 turns, size a piece of brass and test chamber it in your rifle. If the bolt will not close, incrementally turn the die in and size again until the bolt just closes on the brass. This will cause the brass to headspace on the shoulders instead of the belt and prolong the life of the brass.

Really, this procedure is outlined in most reloading manuals in far better detail than I am capable of most times.;)
 
I can't believe that brass in the pics did not have expanded primer pockets. When the primers seat with little or no effort, it's time to cull the brass.

For future reference, when you have a brass failure, it is time to stop shooting and make a critical assessment of the rest of the ammo in that batch. When you have reloaded the same case 3 times, even though the primer pocket is still tight, use a piece of wire with a hook bent in the end to feel for internal cracks in the belt and shoulder areas. Any suspect brass should be culled.

How did you get the case which broke in half out of your chamber? If you used a puller of some kind or a tap, it is possible that you scored the chamber. This could make extraction difficult in the future.
 
joe-nwt said:
With neck-sizing, I have sectioned a 300WM cases that shows no thinning after 12 reloads. But the primer pockets were starting to loosen up so I chucked them anyway.

I would venture the brass in the picture has been reloaded many times. Into the recycle bucket with it.
Click to expand...

......X2
 
Gotcha on the adjusting dies thing now, I've always just pressed till the shell holder hits the bottom of the die..

I got the stuck case out by taking piece of #10 reddy rod, cut a piece of fuel hose, and put nuts on both sides. Welded the one nut on the end of the rod. Removed bolt, inserted tool, tightened the visible nut, that expands the fuel hose. It grabbed the case and pulled it out with reasonable ease. No metal parts actually touched the chamber, inspected it, looks good.
 
Hellpit said:
Gotcha on the adjusting dies thing now, I've always just pressed till the shell holder hits the bottom of the die..

I got the stuck case out by taking piece of #10 reddy rod, cut a piece of fuel hose, and put nuts on both sides. Welded the one nut on the end of the rod. Removed bolt, inserted tool, tightened the visible nut, that expands the fuel hose. It grabbed the case and pulled it out with reasonable ease. No metal parts actually touched the chamber, inspected it, looks good.
Click to expand...

Very crafty!:cool:

Now you just need to master die adjutment....:)

Joe
 
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