I would like some .260 Reminton brass in either Lapua (which offers .243 and .308) or Norma (which offers .243,7-08,.308).

My questions are:
1. Would it be easier/better to size up or down.
2. If I sized up from .243 would I have problems with the necks.
3. If I sized down from 7-08 or .308 would the necks be too thick, and need to turn.
4. Depending which way is best, how do I do it!!!

I prefer sizing up, less chance for necks to get too thick. I use Lapua 243 to make brass for my 260ai. Just run them into my Redding die w/ tapered mandrel & then fireform. You should be able to skip fireforming in a std. 260 chamber. They form up pretty easily as it's only a 1/2 caliber diff.

quote:

I prefer sizing up, less chance for necks to get too thick

Factory chambers are usually a pretty loose fit and the thicker necks may actually work better for you.

I use Lapua 243 cases in my 7mm-08, no problens, its the best brass by far as far as i'm concerned.

I would get a tapered expander for your sizing die and go with the Lapua 243 cases.

I use Lapua or Hornady Match for my 260 & 260 AI....neck down in my Redding FL die...turn necks for the AI..

Neck up .243 brass. Trim to length. I went from .243 to 7-08 with no probs. Shouldn't need any fireforming.

Hi there...
I have a .243 Win. and a .260 Rem. rifle, so I was concerned that if I necked up .243 brass to make .260, that I wouldn't be able to tell the difference between the cartridges after tumbling batches of the two together. I purchased several bags of Winchester 7mm-08 brass, and necked them down in my .260 Rem. sizing die using Hornady spray lube as the lubricant. So far, it's worked perfectly - no donuts or super-thick necks, just brass that works and keeps on working. And, as the main point of this exercise was intended, I can easily tell which brass is my .243 and which is my .260 just by looking at the headstamp.
THe point here is that you don't ALWAYS have to start with smaller brass and neck up... it can and does work the other way around as well!

Thanks guys!! I really appreciate the help!!

Neck down when possible. Expanding necks leaves them thinner than standard brass and is more prone to creating thin spots (uneven neck walls) than necking down. When necking up, part of the shoulder will be moved into the neck area. This may or may not be a problem, but it is avoided in necking down since only the neck, not the shoulder, is involved. As Fjold said, since most chambers have excessively large neck areas, the slightly thicker necks resulting from necking down can provide a slightly better fit, less working of the brass, and more brass to work with if neck turning is needed.

Obviously, necking up works, but going down is always preferable (provided the difference in the parent caliber and the formed caliber is reasonable to begin with.)

Excellent point Gaillo. That has always been my concern on necking up. In my case, I was going from a .243 to a 7-08 as I had rebarreled my .243 to a 7-08 so that wouldn't be a problem. Since you were buying new brass, why didn't you just get .260? Or were you just after one particular brand of brass?
To refute Stonecreeks theory that it is ALWAYS PREFERABLE to neck down (don't you love guys that use terms like that), that works great as long as it's someone else doing it. I went into the Bench Rest room and asked the same question you did but about getting Lapua brass in .243 or .308 to make into 7-08. "By all means", they said, "get .308". I'm sure they're still laughing. To begin with, it takes several passes with a little forster gizzie to get the neck of a reduced .308 case down to 7-08 dims. You can't just take one big bite. Pretty damn tedious when you're working up 100 cases. On the other hand, the necks from the .243's came out surprising uniform.

Hi!

quote:

Originally posted by stillbeeman:
Excellent point Gaillo....
Since you were buying new brass, why didn't you just get .260? Or were you just after one particular brand of brass?

7mm-08 brass is widely available locally, and is relatively inexpensive. By contrast, .260 brass is a mail-order only proposition - at about $8-$10 more per 100. Also, it's only available as Remington (or very expensive foreign brass) instead of preferred (by me) Winchester brass.

I shoot an 8MM/338 Mag. As the name implies, this cartridge is formed by necking down 338 Win Mag brass. When I first rechambered this rifle, I purchased 338 Win Mag brass. I have never picked up an empty 338, they just don't shoot them down here. They do however, shoot 7MM Rem Mag; the spent brass is on every range in the state. I ran one through the sizing die and guess what, it became a perfectly formed 8mm/338 Mag. I've done this for years and have never experienced a problem. Up or down, its your choice.