6.8SPC Long Range and 6.5 creedmor

[Pappabear]

I know the 6.8 SPC was designed for 12.5 inch barrels or shorter barreled guns. And the 6.5 Creedmor is the long range cartridge of choice. My question is this, how does the 6.8 do out to 500 yards?

What are the 6.8 limits? I was thinking about a 16 or 18 inch gun. Would the 6.8 suck for that?

[BullittBoy]

The 6.8 was not "designed" for 12" barrels and shorter. It was designed for 14.5-16" and performs best in this area. The upside is the cartridge is very efficient and looses little velocity so it works well at 10-12.5" barrels. It also does not gain much at all going longer than 18".
It is at its best from 0-350 yards. It will work well out to 500 yards but that is not what it was made for.
The 6.5 is another animal altogether being in AR10 type heavier longer barreled rifles it is designed to be a long range paper puncher and will do well on alot of game too-but at the price of a heavy longer barreled AR10 style rifle.
The 6.8 is a good general purpose hunting/defense rifle with way better performance at close to medium range over the 5.56.
The 6.5 Creedmore would better to be compared to the Grendel, but the Creedmore has more case capacity.
If you want a pure target rifle the 6.5 is a great round from what I have seen, the 6.8 is a great lighter weight hunting rifle and can be used by smaller folks and kids and women with ease.

[markm]

I remember reading an article on 6.5 creedmor... I think in handloader...

I wanted one after that. We like to shoot the hell out of our .308s, but after 40 rounds or so... you're getting fatigued.