Just miked the length of my 308 shells. After firing only lead 200 gr. bullets at 1800 ft/sec. they all have shrunk to min.length.What to do? Marlin

What's the problem?

I suspect you mean the cases are too short after low-pressure shooting.

There should be no safety problem is continuing to use them for either lead or copper bullets.

If they are too short for your crimp die, get a $10 Lee factory crimp and grind the bottom off the inner cylinder to adjust the length. (Mark the shortened crimp die.)

All cases shorten with low pressure loads as they expand to fill the chamber. The sloppier the chamber the shorter they will get. Nothing to worry about at all. Be thankful you don't have to trim them.

Thanks guys for your help. I`ll just shoot them.

Just don't use them for full power loads.
Paul B.

Paul,

I don't see a safety problem in using these for full-power loads.

I have only seen the case OAL get shorter, but have not seen the shoulder move back.

Do you fear that the shoulder has moved back as well, creating excess head space?

The shoulder will not move back and they will be good for all loads. From this point on, I would neck size only. That lets the case fit the chamber better.
There is no problem what so ever and I would load and shoot any load. The only time to worry is when the case grows too long, then they must be trimmed.

Hi y` all. Neck-sizing only, might be a little difficult. I am shooting a 200 gr. Saeco bullet.
I was told to full length resize the empties because I am using an Expander die ,so as not to shave the lead.My cast bullet is about 0.3095. Marlin

Marlin, you did not say, but they should be measured after resizing. If you measured before, that's why they are short.

I can't see that load moving the shoulder back, but very light loads most certainly will. I got partial case separations in .308 after using the cases with 1100 fps loads and a 150 PB and returning to full house loads.

quote:

Originally posted by Leftoverdj:

I can't see that load moving the shoulder back, but very light loads most certainly will. I got partial case separations in .308 after using the cases with 1100 fps loads and a 150 PB and returning to full house loads.

Can you please tell us the details? This is the kind of info that might keep me out of trouble some day!

How many times had they been reloaded? Were you neck sizing or full length? Had you annealed them at all? Where did they try to separate?

Thanks,

They started out as once-fired milsurp, had been full length sized every time, and had been fired 2-3 times with the light loads. They cracked about a half inch from the base.

It may be of some relevance that they had been used in a Mauser 98 with its mighty spring and firing pin. My son got the 98 and I replaced it with a CZ 550 in which the cracked cases occured. There was no evidence of gas leakage or any other problem, just cracked cases.

Thanks.

quote:

Originally posted by marlin55:
Hi y` all. Neck-sizing only, might be a little difficult. I am shooting a 200 gr. Saeco bullet.
I was told to full length resize the empties because I am using an Expander die ,so as not to shave the lead.My cast bullet is about 0.3095. Marlin

There's no reason why you can't neck size. You can bell the casemouth and seat your Saeco boolits. Any crimp die will return the mouth to the proper diameter, and it does not need to be set to crimp. If the neck sizer makes the neck too small overall to seat the boolit without a bulge, it can be honed to a larger diameter without too much trouble.

Leftoverdj,
I am not saying that this is what happened to you, but it is my experience that case separations occur most often when either a) the full length sizer die is incorrectly set to move the shoulder back too much and repeated sizing stressed the case too much, or b) the chamber has excessive head space and the repeated full length resizing of the case keeps pushing the shoulder back, again overstressing the brass. Constantly setting back the shoulder is what causes the brass to work harden and become brittle. As you never mess with the shoulder when neck sizing, the case is custom fireformed to the individual chamber, and even in a chamber with too much headspace, you will not have separation problems. Anyone with much experience shooting and loading SMLE's either learns this quickly or goes through a lot of brass. (I know it is a rimmed case, but there is so much variation in chamber dimensions with the many different contractors all over the world, full length sizing kills cases quickly and they die of head separation more often than not.) Any bottleneck case can have similar problems, and there is quite a bit of variation in .308 chambers, too, especially in semiautomatics, though maybe not as extreme as with the wartime .303's. If your fl die is setting back the shoulders of your cases, you are asking for trouble and very short case life, regardless of whether the loads are heavy or light.
I suspect that the Mauser may have had an overlong chamber, and since they were fl resized after every firing, the brass may well have been worked more than you realize.

Versifier is correct. Full length sizing will make the brass stretch with every shot and the load will not matter. The source of brass moving foreward is just ahead of the web and this will get real thin and crack. Brass will not stretch evenly throughout the case. Military brass seems to be harder and can crack faster.
It also does not matter if you don't set the shoulder back when sizing. You are squeezing the sides in and it still has to expand again when fired. Again, the brass comes from just ahead of the web and case life is shortened. If you take a bent wire with a point on it and run it from the base to the shoulder in a case that has been fired and full length sized a lot, you will feel a slot just ahead of the web. It will crack right there.
Neck size only until the case will be hard to chamber, then full length without setting back the shoulder any more then it takes to chamber the case. Then go back to neck sizing. This will make the brass last longer. If necks start to split, anneal them. I have gone over 40 reloads without losing a single case.
Do NOT anneal revolver brass.

Any time you full length size, the die has to be adjusted until the case will chamber with just a little resistance to closing the bolt. If you are shooting a semi auto, you have to size more and have to accept low case life.