Case head separation

[matt_brown]

I was testing some loads this weekend in my 338 lapua and started having cases blow out. I am shooting book max with a 250 gr bullet but I'm not showing any signs of pressure besides the cases blowing out. After sitting around scratching my head I think there is 2 things that could be wrong.

1 being I am using s&b brass that I have shot 5 or 6 times. The other being that I am bumping my shoulder back too far.

Thoughts????

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[Snowwolfe]

Re: Case head separation

My guess is you are correct on both counts. I never cared for that brand of brass. But if you are loading close to or at max it's not uncommon to only get 3-4 reloads out a case. Try adjusting your resizing die so the case chambers with just the slightest resistance.
If you want to load them hot, well, then you got to pay to play so don't expect long life out of any brass

 

[Deer Assassin]

Re: Case head separation

My guess is you are correct on both counts. I never cared for that brand of brass. But if you are loading close to or at max it's not uncommon to only get 3-4 reloads out a case. Try adjusting your resizing die so the case chambers with just the slightest resistance.
If you want to load them hot, well, then you got to pay to play so don't expect long life out of any brass

ditto

 

[matt_brown]

I'm about over this 338 lol.

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[mr.big]

Re: Case head separation

that has nothing to do with pressure and everything to do with headspace

 

[MUP]

Re: Case head separation

Is this a case of full length sizing each time, rather than neck sizing possibly? I reckon fl sizing will cut the life of a case as opposed to just neck sizing.

 

[7mminatree]

Re: Case head separation

I would have your headspaced checked. If it passes, then you can extend your brass life with a good neck sizer die.

 

[matt_brown]

I FL size all my brass (223, 22-250, 243, 25-06, 300 win mag and the 338 lapua) I have always ran my die down till it bumped my shell holder and then just a bump more so I have full contact. The 338 is the only cartridge I have ever had case head separation on that is why I was leaning more towards weak poor quality brass. Since this has happened I have studied the "proper" way to FL size brass and wow there is such a fine line when it goes from same size to 0.001-0.002" bump to a 0.006-0.008". Why have I not had this happen with other calibers? Is it because the 338 is so big/powerful? I shoot nosler, Win or lapua brass in everything EXCEPT the 338 in which I shoot S&B brass.

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[mr.big]

Re: Case head separation

I tell you what I have,,is maybe 50 pieces of Lapua 338LM brass that has been loaded 7-8 times and has had the necks turned,,if you want it PM me your address and I will send it to you,,it was annealed a couple cycles ago,,if you FL size it correctly it should last 4-5 more cycles,

 

[matt_brown]

Pm sent

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[mr.big]

Re: Case head separation

dont risk using that brass and trash it and I will send what I have left from my 338 venture,,

 

[matt_brown]

Mr. Big.... you are the man.. thanks a bunch

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[mr.big]

Re: Case head separation

no problem man,,back your FL size die about 3/4 turn and size one case,,and try and chamber,,turn die down about 1/16th turn until you can chamber a round with just slight pressure,,I will send shellholder also as all different headstamp 338LM brass takes a different shellholder,,

I doubt getting back into 338 any time soon,,IMO unless you are shooting elk past 800 yards or shooting targets at 1500+ there are other rounds that will do about the same with much less fuss and expense

 

[megalomaniac]

Re: Case head separation

that has nothing to do with pressure and everything to do with headspace

x2... have a gunsmith check your headspace before shooting it again

 

[Sniper]

Re: Case head separation

Based upon what you stated about how you set your dies I think you are pushing the shoulder back too far. I do the same thing Mr Big said, just run my FL sizer down to where it just barely touches the shell holder, resize and see if it will chamber. If not then in very very small increments I will turn the die down and repeat until case chambers with minimal resistance.

 

[BobTail]

Re: Case head separation

ANYONE who reloads needs to have the correct tools. Get yourself a Hornady Headspace tool and a decent set of calipers and learn to use the tool. Your rifle's chamber is probably NOT the problem and is within specs. Every chamber is different and guessing how far to adjust a resizing die by any other means is a recipe for trouble ....... as you have seen. The tool is inexpensive and will not only extend the life of your brass but will also prevent personal injury .... which you are very close to having. You can get the tool at midwayusa or brownells. It comes with detailed instructions and there are also youtube videos showing it's use.

Or, you can continue to press your luck by guessing.

 

[Snowwolfe]

Re: Case head separation

ANYONE who reloads needs to have the correct tools. Get yourself a Hornady Headspace tool and a decent set of calipers and learn to use the tool. Your rifle's chamber is probably NOT the problem and is within specs. Every chamber is different and guessing how far to adjust a resizing die by any other means is a recipe for trouble ....... as you have seen. The tool is inexpensive and will not only extend the life of your brass but will also prevent personal injury .... which you are very close to having. You can get the tool at midwayusa or brownells. It comes with detailed instructions and there are also youtube videos showing it's use.

Or, you can continue to press your luck by guessing.

While the tool you are recommending may work well so will a simple adjustment of the sizing die. My practice is to leave the bottom of the die above the shell holder by about 1/16th of an inch. Then start with about 5 cases that were fired with stiff loads. I resize them then see if they chamber. If they don't I screw down the die 1/4 turn and try again. This gets repeated until the bolt will close with little resistance.
There are variations in every chamber cut and in every sizing die due to tolerances and to chambering reamers being new or worn. The important thing is to match the ammo to the rifle with the same set of dies on the same press. Will my suggestions take care of all head spacing issues? NO. But if you want to fine tune your ammo to make sure you can get the most case life possible give it a try.

 

[BobTail]

Re: Case head separation

Why go through all of that sizing and die adjusting when you can spend $30 and get a measuring tool that does the job correctly? That's a very small amount of money to spend on such an important tool. Same for the Hornady OAL gauge (or equivalent). Every reloader should have these 2 tools on their bench.

 

[Snowwolfe]

Re: Case head separation

Why go through all of that sizing and die adjusting when you can spend $30 and get a measuring tool that does the job correctly? That's a very small amount of money to spend on such an important tool. Same for the Hornady OAL gauge (or equivalent). Every reloader should have these 2 tools on their bench.

I don't mind spending 5 minutes adjusting the dies. I simply don't need one of these Hornady tools..