LC 308 brass to 260 brass?

[Morgan Johnson]

Has anyone made 260 brass out of 308 brass? I have 400 pieces of LC brass. My plan was to neck it down to 7mm -08 and then finalize it with the 260 FL die, trim, and if need be trim neck thickness. Is there anything I am missing in the process?

 

[STOMP442]

Nope, that covers it. I have made a bunch of cases this way ad it works great. In my experience, the necks always need to be turned for best results.

 

[HTSmith]

You got it. The 260 I did it for had big neck and I didn't have to turn for it.

 

[jpretle]

You can got clear down to 243, if you want. Done so many, many times and have never had to trim the necks. However, i have done so a couple times just to make things a bit more concentric. Can't say that really helped much, though.
I am currently running 308's necked to 243 and FF'd in an Ackley chamber.

 

[JLT]

You may want to remove the expander ball from the 7-08 die - no sense working the brass more than you have to.

 

[Shaggy357]

I purchased a bunch of military .308 brass last year for my .308, 7mm-08, and 260...
I made a couple hundred up of each caliber this past winter. They have been loaded and ready for a couple of months. Shot some of the 260s this past Saturday. Very happy with the results. Changed scope to higher magnification and hope to try them at longer ranges this coming weekend.

 

[sbhooper]

Just run them through the die and turn the necks if it makes you feel better. Hornady match .308 is the only casing that I have used for my .260. 1/2 moa.

 

[DRNewcomb]

You do have a way to anneal the brass? You'll need to anneal before and after.

 

[Shynloco]

Has anyone made 260 brass out of 308 brass? I have 400 pieces of LC brass. My plan was to neck it down to 7mm -08 and then finalize it with the 260 FL die, trim, and if need be trim neck thickness. Is there anything I am missing in the process?

I've recently done exactly that in one step and it worked great. And do lube the inside/outside of the necks. I do recommend turning the newly formed 260 brass ever so slightly to remove the high side which I found most of my LC .308 did have. And when I say "slightly" I mean slightly. I use a 21 Century Turning Lathe which made the process very easy. I will add that I've bought Lapua 260 brass since, but found little difference in outcome on the target. But if you are chasing best accuracy and consistency in every detail including brass weight, Lapua will win out as a more consistent casing.

Alex

 

[Loggins J]

I make 260 brass out of 308 I run them in a 7\08 then a 260 it works fine for me

 

[sbhooper]

You do have a way to anneal the brass? You'll need to anneal before and after.

Nonsense.

 

[Morgan Johnson]

I did anneal the brass. My plan is to run them through 7-08 dies then the 260 and trim. I also purchased a neck trimmer just in case that makes a difference. I appreciate all of your advice and input from everyone thank you!

 

[msinc]

I have done this a lot...I have never bought or otherwise attained any caliber specific cases for my 7mm-08's or 260's. Every round that has ever been down the tube was made from once fired Lake City LR brass. Eventually I do anneal the cases, but I have never done it "before and after" the sizing down to whichever caliber I am making. I have tried it just before, but it made no difference....the fact is brass either needs to be annealed or it does not, and once fired???? Doubt it.
Somewhere in the middle of all this I got lazy and decided to try leaving out the 7mm sizing and just going right to the 260 die....worked perfectly. I also found that if I had a lot of cases to size I lubed with Ivory Ultra dish washing liquid. Just squeeze some into a big Ziplock bag and throw in some cases. Work it around until all the cases have a coating and dump them out on a big trash bag or clean table to dry. Let them dry and enjoy effortless sizing.
I recently completed a 308 build and needed some brass. All mine was either 7mm-08 or 260 so I just sized it back up, no problems. I have taken it all the way to 243, but there was always a little ripple on the shoulder until it fire formed out with the first shot, otherwise, no issues. As to neck turning, I have done it and have tried it without. Seems to not be a factor for me...I really doubt sizing cases can significantly, if at all, "thicken" case necks....if they did better because you outside turned the necks then the cases probably needed it to start with.

Edit: almost forgot....because some military chambers are "bigger" for lack of a better term, you might want to first run them all thru a 308 FL sizer die if it seems like it is taking more effort than it should. It is better to try and alter the neck without having to also work the entire case that has been fired in a big chamber at the same time.

 

[Shynloco]

Edit: almost forgot....because some military chambers are "bigger" for lack of a better term, you might want to first run them all thru a 308 FL sizer die if it seems like it is taking more effort than it should. It is better to try and alter the neck without having to also work the entire case that has been fired in a big chamber at the same time.

GREAT POINT!.. I forgot to mention in my earlier post that I run all the Lake City brass through a Redding Small Based .308 Die before I perform the neck down procedure so that the newly formed brass/necks better fireform to my .260 chamber. Might not need it, but I'm thinking the new sizing will all be as close to the same as possible.

Alex

 

[msinc]

GREAT POINT!.. I forgot to mention in my earlier post that I run all the Lake City brass through a Redding Small Based .308 Die before I perform the neck down procedure so that the newly formed brass/necks better fireform to my .260 chamber. Might not need it, but I'm thinking the new sizing will all be as close to the same as possible.

Alex

Yes sir, I often see what I would describe as a non-concentric "wave" of expanded brass on the case just above the case head at the area of the web. It is a good idea to use small base dies to help and get rid of this as much as possible. If it's not gone or at least reduced as much as possible it seems like it could interfere with a good positive fire form in your chamber.
I don't really see this too bad on Lake City LR brass of course, but if I get some of the old machine gun ammo that was fired in an M-60 it is almost always there. Used to see this on 30-06 cases that were fired in a M-1918 too. Free brass is nice and machine guns have big chambers. It cant be good to just leave it there.