Thread: Small primer vs large primer brass in 308

Just my experience on this make of it what you will

To make 260 brass from 308 is pretty easy, anneal it and run it through a sizing die ( 308 first if its been once fired already ) as an easy step next size it down to
7 mm 08, now size it down to 260. and you have ready to run 260 ammo. ( in theory )
Measure your case wall thickness at this stage ( by running 308 down to 260 the case neck walls are now thicker.) Load a dummy round with the projectile you intend to use and see if it chambers in your rifle. If the wall thickness is up around 17 thou you may have to outside neck turn at this stage as they may not chamber in your rifle.

I did this as an excercise using once fired mil surp brass ( there are no caliber designations on it ... just the year of manufacture usually ) ( I thought this was good as there was no chance of someone picking up a bullet and getting it wrong )

I had to neck turn down to 15 thou to get easy bolt closure. I made 200 cases and havent gotten through to a second loading yet, I didnt get brilliant concentricity from this But I hope that from fire forming a couple of times they will conform to my chamber. I can hand pick the low runouts for special occasions and the other stuff is good for when you dont want to spend time looking for brass.

Would I do it again .... yep, would I use mil surp again .... probably not. ( I suspect that a few loose chambered M 60's may have fired the brass first)

Mil surp brass is pretty heavy duty so longevity should be good, but the down side is the case capacity is down a bit

308 LC reformed ...... case capacity 52.3 grains
7mm 08 hornady / win reformed ....53.3 grains
260 Rem brass........55.7

So from rem brass to mil surp you loose nearly 3.5 grains of capacity, i dont know what the capacity of Lapua 260 or Lapua 308 reformed would be.
I WOULD BE INTERESTED TO KNOW THOUGH