Resizing 308 to 260

[bflee]

What do I do to get rid of the donut in front of the shoulder? A neck trimmer wont do anything for that!
Do I need to order some 260 brass?
I have alot of 308, so I had to try.
I can get some 243 free if it will work better.

[stomp442]

Sounds like your not sizing all the way down. After full length sizing you will need to turn the necks a bit. The cost of a quality neck turner is just as much as a nice 100 count box of Lapua cases.

[bflee]

Thanks stomp! I just turned my die down a hair and got rid of the donut! It worked great! I may need to turn the neck, but I dont see it right now. I cut one open after resizing and I cant see the anhthing onthe inside either. I dont have any 6.5 bullets right this minute but as soon as I can I am going to try and reload one. I did notice the resized 308 are a hair shorter than the 260 brass after the process. Will this cause me any issues? It chambers good as is. Anyone with any input?

[stomp442]

They will grow and stretch after firing and resizing again nothing to worry about there. You will indeed need to turn the necks I've had to every time I have formed cases. Even if it chambers fine I have found the neck tension to be excessive and after turning things came together much better as far as load development and consistency. Groups shrank way down after turning.

[BillPa]

I did notice the resized 308 are a hair shorter than the 260 brass after the process. Will this cause me any issues? It chambers good as is. Anyone with any input?

None other than allowing a bit more gap space, the distance from the end of the case mouth to the start of the free bore for powder residue and carbon to collect. If you clean the chamber along with the bore it usually isn't a problem.

Bill

[gotcha]

What do I do to get rid of the donut in front of the shoulder? A neck trimmer wont do anything for that!
Do I need to order some 260 brass?
I have alot of 308, so I had to try.
I can get some 243 free if it will work better. Actually, the .243 WILL work better. Case oal is 2.045" VS. 2.015" for the .308........... Necking .308 down to 260 yields .044" of movement resulting in thicker neck walls. Necking .243 up to 260 only changes neck dia. by .021" resulting in SLIGHTLY thinner necks. If you've got the cash the Lapua 260 brass is your best bet.

[Steelhead]

Actually, the .243 WILL work better. Case oal is 2.045" VS. 2.015" for the .308........... Necking .308 down to 260 yields .044" of movement resulting in thicker neck walls. Necking .243 up to 260 only changes neck dia. by .021" resulting in SLIGHTLY thinner necks. If you've got the cash the Lapua 260 brass is your best bet.

I use 243 brass and have been getting good results with it.
You can get doughnuts doing it that way also but a reamer or neck turner fixes that.
Win brass has thinner shoulders and less chance of a doughnut.
I have a tight neck so I neck turn anyway.

[gotcha]

Steelhead............ Good point on the Winchester brass.

[gotcha]

What do I do to get rid of the donut in front of the shoulder? A neck trimmer wont do anything for that! A do-nut on the exterior neck is NORMAL when using a 260 die to convert a .308 case since the 260 has a longer neck/shoulder to base dimension. Your case will chamber but be a sloppy fit with too much head space! When using the 260 die on .308 cases simply adjust the die downward until you get slight resistance to closing the bolt.(this is called: creating a false shoulder) This results in the case being trapped between the neck/shoulder junction of the chamber and the bolt face, which is what you want when fire-forming the shorter bodied .308 case. Do the same adjustment with a .243 case and you will push the longer .243's entire shoulder back until you get slight resistance to closing the bolt. You first need to know if your chamber is Factory no turn neck or a custom tight neck. Any questions??

[Robinhood]

Gotcha, I was aware that the 260 case OAL was longer but not that the head space was different. It has always been my understanding that the head space for both cartridges was the same. Both the 260 and 308 have a chamber head space of 1.630 to 1.640, Case head space 1.634 -.007. Can you verify your information in case I am mistaken.

[bflee]

I am stamping them out now guys. Thanks. I dont shoot the 308 anymore but have alot of brass. It just makes sense to use it.

[gotcha]

Robinhood, My answer was intended to bring safety into the issue. Without a Head-space gauge there's no telling what the exact dimensions of Bflees chamber actually are. The pluses and minuses of Saami specs plus the possibility of a bbl. Mfg. getting the dimensions "pretty close" would cause me to 1st try the false shoulder method. Secondly, I'm not talking about cartridge case OAL I'm talking about dimension of brass comparing neck/shoulder junction to base measurements. Just saying I've done a lot of reforming and I'd rather be safe than sorry. Been there, done that. The method I recommended would assure bflee's brass would properly fit his chamber and not cause safety issues...... There are specs. then there's the real world, if you know what I mean. :)........... One other thing: Is Bflee's brass mixed head stamp? once fired in more than one chamber? Factory fresh but multiple lots. Fired semi or full auto? Who knows?

[Robinhood]

Thanks for the clarification. Safety is always a good thing.