I've looked and cant find any? it it out there?

No, but they do make .308 brass. If you read some of the old threads in this site you will see that many guys neck down Lapua's .308. They also make .243, but from what I have read recently, necking a .243 up is more challenging than just necking down the lapua .308 brass.

Buy the .308 brass and neck it down a little at a time, checking for chambering after each adjustment of the die. Once you get a slight crush fit, you're ready to trim and load, and with no headspace issues.

I was thinking of the 308 brass,,,just starting to reload though,,,,how challenging is this?

Necking .308 brass to 7mm-08 is a piece of cake. Just run them through your die. That's about it. Almost.

I recommend chamferring the case mouths inside and out before you start necking down, though, and use enough lube on the neck to keep from scrunching the necks (I've done that, too). Adjust you die to where it just touches the shell holder, and then back off the die a couple of turns. Try running a case into the die. If no neck sizing occurs, turn the die down a quarter turn and try again. Check for fit in your rifle's chamber each time you change your die adjustment. Once you get close, go to 1/8 turn adjustments on the die until you get a slight crush fit when you cam the bolt closed. You should have a perfect fit.

The last cases I bought for my 7-08AI were Winchester .308 cases. I bought 100 cases from the same lot. They were unbelieveably more uniform than the 7-08 brass from either Remington or Winchester. If they weren't, I would have returned them and gone with Lapua. I buy Lapua 6BR brass, and it is absolutely beautiful brass, drilled flash holes and all. But since the Winchester brass I bought in .308 is so nice, I believe I'll just stick with that for a while. Actually, I've already got several hundred 7-08AI cases already fireformed and have no need for more new brass. It's just that every time I wander into a gunstore between appointments, I wind up spending money. I hope you don't wind up with the same disease. It can be very contageous, and it is spread prolifically on this forum. Good luck.