As posted in the small caliber section,

What is the loaded round neck diameter supposed to be for the .260 Remington?

Thank you.

0.2970" MAX I believe

Thanks Joe

My Douglas factory reamed 260 chamber measures .298" at the end of the neck.

.308 brass necked down with a .264" bullet will measure .297".

You should be able to get away with no turn, right?
Wrong.

Everybody tries 308 brass on 260, because they have 100,000 pieces in the bomb shelter, but it is not worth it.
Enough things go wrong.
Turning the necks is too much trouble.

The good alternatives are 243, 260, and 7mm-08 brass.

Clark,

I neck down a lot of range 308 brass down to 260 and have NO problems with it in any of my 260s...

I Neck down Win and Fed 308 brass all the time with no problem

LC match have to turn the necks.

You guys are lucky.
I get bolts hard to close and primers falling out 5% of the time.

quote:

Originally posted by Hunt-ducks:
I Neck down Win and Fed 308 brass all the time with no problem

LC match have to turn the necks.

I tried necking down some 308 to 260 & had to do it in stages. First to 7mmthen to 6.5. I was losing way too many cases w/ folded/creased necks. Then they were too thick for my chamber & had to be neck turned. Way too much work. So I am using Lapua 243 or Nosler custom 260.

LC and Federal both have problems 5% of the time for me. I think it may be the donut problem pushing high pressure loads over the line into short brass life.