Forming .260 brass

[rugerdog5]

I've decided to build a tactical rifle in .260. I've read a little on this and noticed most people buy 7mm-08 brass and neck it down. I want to know the process for using 308 brass because I have a few thousand pieces of LC match 308 sitting in buckets in my garage. So needless to say I don't want to spend money on brass when I can do it myself. Thanks for any imput.

 

[RT2506]

LC brass is really thick so after you do neck it down you will most likely have to turn the necks. They will not hold as much powder either so you need to really back off and work up your loads from the suggested loads. Also I have found that 260 Rem cases made from 308 cases have short necks when finished. When my buddy and I made cases for his rifle we used 243 Win and necked them up using a tapered expander ball in the size die. We did make some from 308 cases by just running the case into the FL size die without the expander ball in it. Then run it through a second time with the expander ball in the die. We used WW cases. We lost some cases due to crushing and wrinkling. It would be best to size in steps. I would suggest that if you have access to a 7mm-08 die that you run your cases into them first without the expander ball in the die then into the 260 die. Be sure to check the neck wall thickness and measure with a bullet seated the diameter of the neck against the diameter of your throat in your rifle remembering you need a couple thousands clearance for expansion to release of the bullet.

 

[J E Custom]

LC brass is really thick so after you do neck it down you will most likely have to turn the necks. They will not hold as much powder either so you need to really back off and work up your loads from the suggested loads. Also I have found that 260 Rem cases made from 308 cases have short necks when finished. When my buddy and I made cases for his rifle we used 243 Win and necked them up using a tapered expander ball in the size die. We did make some from 308 cases by just running the case into the FL size die without the expander ball in it. Then run it through a second time with the expander ball in the die. We used WW cases. We lost some cases due to crushing and wrinkling. It would be best to size in steps. I would suggest that if you have access to a 7mm-08 die that you run your cases into them first without the expander ball in the die then into the 260 die. Be sure to check the neck wall thickness and measure with a bullet seated the diameter of the neck against the diameter of your throat in your rifle remembering you need a couple thousands clearance for expansion to release of the bullet.

+1
I would also anneal the LC Brass before you even attempt to size it down that far and
you get buy using the 308 brass .

I tried the same thing for my 7/08 and it worked out OK but you may also have to go
in steps (308 to 7/08 then turn the necks and finish sizing to 6.5)

It will help to turn the necks before you size the down any.

I hope this helps. It's a lot of work but if you have the brass it wont hurt to try.

J E CUSTOM

 

[rugerdog5]

Thanks guys that's what I was curious about. I might just invest in a couple hundred good pieces of 260 brass when I get done building the rifle which will be awhile since I'm buying a piece at a time the economy is really screwing with my gun addiction haha. I'll keep my 308 stock pile for my 308s. Again thank you

 

[boomtube]

Necking down that far will be easy IF you use a good case lube - I prefer Imperial Die Wax or Unique, finger applied. Annealing before doing it may or may not be needed, try it both ways and see how it does. For sure, anneal it afterwards or it will split fairly quickly. As mentioned above, it will be really easy if your own or can borrow a 7-08 FL die as an intermediate step. But, I've taken .308 to .243 in one step with a high rate of success.

GI cases tend to run a little thicker than commercial but not massively. And it won't change massively when you size it down that far either, you'll add about 17% to the thickness, couple thou maybe? If it needs turning or not depends more on your new chamber than the cases, as such. When you get the new rifle fire a few factory loads in it, measure the fired neck diameter to see if your reformed cases/oaded ammo is larger or smaller. If your stuff is larger you will need to turn them down to about the diameter of the fired cases.