.243 from .308 small primer cases?

[Phil]

Do you move the shoulder, either forward or backwards, while forming .308 Lapua brass to .243????

Yes i know Lapua makes .243, i`m after a small primer case.


Phil.

 

[Quickoz]

Start high and work lower with a few test cases. Many people here in australia with 7mm08AI, 260AI and 243AI.

 

[DocBII]

phil,

I just necked them down when I tested making .243 from .308 Federal brass. Did neck turn them first, still only got so-so results. The neck ended up way short of a normal .243, about 0.050 short.

HTH,
DocBII

 

[Phil]

phil,
The neck ended up way short of a normal .243, about 0.050 short.

HTH,
DocBII

Doc,

This indeed helps, i was afraid of them being short.


Phil.

 

[nastynatesfish]

I anneal it. Hit it with a 7-08 sizer then a 243 sizer. Did the same for 260

 

[Phil]

I anneal it. Hit it with a 7-08 sizer then a 243 sizer. Did the same for 260

Did it come in short for you too, or did the annealing do the trick???

Phil.

 

[spclark]

Did it come in short for you too, or did the annealing do the trick???

By the numbers shown in cartridge drawings elsewhere here you'll see .243's spec'd @ 2.0449" max. where .308's just 2.015", some .30" shorter... 1/32".

Keeping in mind that brass 'grows' with use .243 cases made from .308 ought to get to their design-max length after a firing or three. I routinely trim new Lapua Palma cases to 2.005" before first use, keep an eye on 'em as they get resized. When they hit 2.015" they get trimmed again.

Years ago out of desperation I made 98 6XC cases out of a new box of Palma brass. Took awhile & several steps but I'm still using 76 of 'em this year. Ought to work fine for .243 too just be mindful of potential for chamber neck carbon build-up after shooting cases that are shorter than factory-size if & when you switch back. Depending on how generous your chamber's neck diameter is, it may or may not be a problem.