Making 243 Brass out of 308

R

roc1

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Has anyone made 308 brass into 243 without having the donut in the neck? I have tried to make 6.5 Creedmoore and had donut and seems like few I tried doing on 243 same problem. Reason doing it I no longer have 308 went to 6.5 and have several pieces of Lapua 308 need to use not waste them
Thanks
Roc1
 
Has anyone made 308 brass into 243 without having the donut in the neck?
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Go one step further, I have formed 22/6mm Remington improved from 30/06 and 25/06. By the time I got to 243/6mm the neck was almost closed off.

There is a difference when necking a 308 W down to 243 W. I have a 243 reamer die, for me it is a matter for forming the case with a forming die then sizing with the neck reaming die. After sizing I run the reamer through the neck.

F. Guffey
 
Look up Redding sight. They make dies for forming odd cases and they might have just what you are looking for.
Good Luck
 
Some years ago, I formed several hundred military RA stamped 7.62 cases to 243 with few issues. They all had a small crease in the neck, which ironed out on first firing. Annealed the necks afterward, and they're still holding up. Don't remember any donuts, but it's been a while.
 
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In 2002 I necked down some 308 brass to 243 and loaded it up to =~~ 75kpsi.

Because the thick necks pinched the bullets, some of the pressures were higher.
 
In 2002 I necked down some 308 brass to 243 and loaded it up to =~~ 75kpsi.

Because the thick necks pinched the bullets, some of the pressures were higher.
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Clark, You chambered a round and then pulled the trigger? And the rifle handled like a doll buggy?

When the trigger was pulled the flash hole was destroyed, and then? You chambered another round.

Bruce Hodgdon came to our house, my older brother was shooting 10' high into a river bank at 100 years. Not once but 5 times. My older brother had to hammer the bolt open ever time. Mr Hodgdon never asked him why it took 5 shots to determine something was drastically wrong.

F. Guffey
 
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I went home after the last round.
I had converted that 1938 Turk to 243 and trued the action.
I have not shot it again in the 13 years since.
It took me a while to understand the importance of pinched necks.
I've got it now.... I thought.
Then in 2014 I went out into the desert to shoot a Glock 20[normally a 10mm] with 40sw ammo in a full support aftermarket barrel over a chronograph. I loaded long as would feed from the mag. The work up was prematurely halted by brass failure. It seems I forgot to throat the new barrel. The bullet does not like to be stuck from the sides nor the front.
 
I would like to ask and discuss this same question. I have well over 100 lake city target grade .308 from a known rifle. It appears from these comments that shooting the ammo as is after forming is not to be done. That the brass must be reamed to proper dimensions.

I don't have a set of internal reamers or even the tool to do it. I do have a lyman outside turner that I have experimented with. The device is set up to cut to a chosen thickness by positioning a cutter by a mandrel, reaming a the outer layer to a not particularly beautiful finish that can be checked with micrometer or caliper for brass thickness.

The basic question is, would an outside turner removing a heavier than normal layer of brass be adequate, as opposed to an internal reamer?

I have no intention of running this stuff out and firing the re-formed military brass at full pressure.

i'm not even sure that this is worth the trouble. I can probably get $25 for the lot, and even factory new brass sells for only about $50 per 100, maybe 70 after Sh.
 
Nevermind. Looking at my old load notebooks, I noticed my memory needs a refresher. :rolleyes: I had posted that I reamed.....turns out I was wrong. The records don't lie.

My LC 7.62 cases were first resized with a normal RCBS FL .308 sizer, then sized again with a normal RCBS FL .243 sizer. No reaming after all...
I do have a reamer but it wasn’t needed.

I did a little search and found about 50 cases of LC brass that I sized down years ago to .243 from .762. For some reason I never got around to loading this batch…..but since I have it, a measurable record to go along with my written reloading journal entries dated in 1975 for similar LC-.243 loads. Most I've shot. But I always keep “one” finished cartridge as a record....and then I also found some once fireformed. I took pictures....below.

Anyway, I thought I'd post my successful experience necking LC down, which turns out was done a little differently from what I first remembered, simpler. No form dies, no reaming was necessary on that old LC 1960's 7.62 NATO brass, so I'm doubting such is needed with lighter brass either.....course it depends on the chamber. I don't know, but I wonder if the intermediate step, size to .308 might reduce the donut effect....because I don't see or feel and inside donuts on this brass......another reason I didn't ream.

The rifle I shot it out of was a Remington 600 Mohawk. A very accurate rifle that liked the LC-243 just fine.............why did I quit the LC-243 project?......weeelll, I bought a .308 AR and used up my brass that way.....but I may have to start up again, as I have acquired a lot more LC brass now.

In the following PDF file, explain the neck down steps I used. I tabled the neck diameter information I measured off this brass, along with the appropriate SAAMI measurements. I also added pre and post-fireformed case length measurements of the LC brass. View attachment 100051

Below, left to right, LC 68 sized as above to .243W, Loaded LC-.243, Fired LC-243 (that one is LC 62.) Notice the line on the shoulder from the 7.62 shoulder edge, gone on the fired-formed case on the right. These necked-down cases are shorter than factory 243W. See the PDF above.

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These were not reamed...again, see the neck dimension data on the PDF link above.

Notice the spent primer on the fire-formed brass doesn't show any pressure signs nor is there any head smear. That sample is representative. The load used was 38 grains of IMR 4350. (1975 powder)
IMG_2568.jpg


To tell you the truth, I think .308 to .243 is a natural. Other than sizing twice (no big deal) and in the case of military brass reaming/swaging primer pockets, it isn't any more trouble than reloading anything.

The only thing I didn't like was the idea of .308 headstamps on .243 brass.......of course in the case of LC brass, there is no .308 in the headstamp. The price is right too.
 
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Sell your .308 brass to someone. I have formed a lot of cases over the years out of necessity, but unless you are doing it just to learn the process, it is not worth it with common brass. Buy more dies. Buy something to ream or turn necks if it is heavy military brass. Maybe fire form. Probably anneal. You deplete your brass stockpile. Now what? Buy more .308 brass because you invested in the other stuff? You almost always get fall off when forming brass. In the long run it is a lot cheaper to buy the correct brass if it is common.
 
that's been my thought all along, but if it would be a simpler process it would have been worth the experience. I'm sure that I can find someone who'll bite on the brass for about a quarter each.
 
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