Re-sizing .243win to .308win

B

butta9999

New member
G day all, i own both a .243win and .308win and reload for both. My question is can i F/L re-size my .243 brass to suit my .308.

I experimented this morning by running a .243 case into my .308 F/L die "well lubed of course" and to my surprise it looks fine.

Does this weaken the brass around the neck and shoulder area.

Case length is a little long 2.020, i trim to 2.005 after doing so is there anything else i should know.
 
N

Nomadicone

New member
You don't even need to FL resize. Just lube the inside of the neck and run the expander through the neck. Of course if there is an old primer in the case you'll have to run it down far enough to decap it.
 
L

Loader9

New member
You can do it but yer not gonna like it. The necks shorten as you expand them, the necks will be paper thin, and splits will probably happen with every case. I'd buy the correct brass or better yet, find some military match brass and anneal the necks. It'll last forever.
 
B

butta9999

New member
Just as an experiment i sized 10 .243 into .308 and did not experience one split neck. Is this just a fluke, or do you mean after i fire the reload.

I did find with all of the cases they did need trimming. I will not be reloading these until i here more about it.

I could imagine the brass around the neck would be weakened as it goes from .243 of an inch to .308
 
N

Nomadicone

New member
I have reloaded for several calibers which require this type process. I have reloaded 6 PPC (220 Russian neck opened to 6mm & fire formed) 7mm TCU (223 with neck opened to 7mm) 30/338 (7mm Mag opened to 30 cal) and none have ever been a problem using the method I discribed above. The key is lubing the inside of the neck. I like Imperial sizing wax for lube then wipe it out with a Q tip.
 
P

PA-Joe

New member
You are going to have to find a way of clearly marking those rounds since they will have a 243 head marking. If you put a 308 reload into a 243 barrel you are going to have a problem. 308 brass is next to free. Why risk a confusing head marking.
 
R

Rifleman1776

New member
I wouldn't do it. Yes, you will weaken the neck.
I don't think caliber markings would be a problem. The difference between the two calibers is obvious. I resized a lot of .308 brass down to .243. But, it was for me, not the ignoramus next door.
 
W

wncchester

New member
My factory case necks are usually about 13 thou. Expanding .243 necks to .308 will leave the necks about 20% less. Makes them about 10 thou on average but they would be even thinner one one side than the other. Thin necks will crack much sooner than normal.

A personal opinon; necking cases down works good because the change is to thicken them. That's usually insufficent to cause a problem but when it does it's easy to deal with. There is nothing we can do to necks that are too thin. But, as you have proven, it can be done.
 
O

oneoldsap

New member
I didn't notice till after I posted that you were from the land down under . Are .243s really more plentiful than .308 , you folks are part of the U.N. aren't you .
 
D

Dave R

New member
you folks are part of the U.N. aren't you .
Click to expand...
Just to clarify, I think he's asking if your country used 7.62 NATO, and if you have access to surplus brass. Given Oz' gun laws, you may not have the access we do.

I also get a lot of .308 brass just by picking it up at the range. Is that an option for you? Nothing like free brass to make a good trip to the range even better!
 
B

butta9999

New member
The reason i have so much .243 brass is i bought my .243 eleven years ago. I have hundreds of empties. I only bought my .308 six months ago, so i thought i might make the most of the empty .243.

No at my range the range official collects all of the empties.

Surplus brass does not come by too easy.


I might try loading 10 or so and see how i go.
 
D

Dave R

New member
I have had success reforming .284Win brass to 7.5 Swiss (.30 cal.) That's a smaller increase in neck diameter than you are doing, but I only split 3 out of 200 necks when doing the initial resize, and all pieces of brass have been through 3-4 firings and no additional split necks.

Hope that indicates that you'll have success, too. Let us know the results of your test.
 
You must log in or register to reply here.
Top