Own a tactical in 26" barrel, have a young shooter who used it quite well at 600, the beauty of it was , recoil was easy on her, and her mom 
So, how would theoretically a 6mm creed do if I build them a rifle with a 30" barrel, will this caliber perform at 1000 yds for F open?
(I can reload 6 creed and have plenty of brass for it, it will keep it simple)
I also thought about a long barreled 6.5 creed, since I have brass, dies, and I can use some of my 142 smk, but not many people have ventured down the 6 and 6.5 long barrel rifle road it seems. Any info is appreciated.

So, how would theoretically a 6mm creed do if I build them a rifle with a 30" barrel, will this caliber perform at 1000 yds for F open?
(I can reload 6 creed and have plenty of brass for it, it will keep it simple)
I also thought about a long barreled 6.5 creed, since I have brass, dies, and I can use some of my 142 smk, but not many people have ventured down the 6 and 6.5 long barrel rifle road it seems. Any info is appreciated.