stepping up long range

[Outlaw6.0]

If you're really set on factory ammo for now, i'd suggest the HSM Extended Range Ammunition, most (if not all) are loaded wit Bergers, which have the capability of offering better accuracy at extended ranges. The few review i've read have been fairly promising, I would tend to thing they would be the most accurate "way out there", unfortunately you'll never know until you try them.

The Hunting Shack Ammunition

[liltank]

Got to be honest with ya, anything in the 180 bonded bullet group is going to work very well to 800yds. The bigger problem is accuracy. I'll agree with Federal premium, and the Winchester 180 Ballistic tip will work rather well also. RWS has a high penetration round on sale that is a 184grn bullet. The BC isn't great, but have a sneak'in suspicion it will be deadly. Midway USA has the RWS on sale. They are great prices and will give you outstanding brass to reload with.

Tank

[dig]

2nd on the HSM ammunition. I normally start any new rifle with a box before starting load development. They are loaded with Berger's (normally a little lighter than I prefer) but perform very well and are actually less costs than other premium rounds. HSM is great to work with. I believe the load the GunWorks product.

[Firecat]

You could also look into the bullets that Gunwerks sells. This is what they offer for their turnkey systems and are being shot out to 1000 yards regularly. That being said I think they are probably just the HSM mentioned above, wrapped in Gunwerks packaging. Here's the Link.

Gunwerks - Ammunition

[ATH]

IMHO you're going about it backwards. If you're going to practice enough to shoot game at 600-800 yds, you will be able to actually save money by buying basic (but quality) reloading equipment and rolling your own, vs buying premium ammo at approximately $3/shell. Getting the gun squared away doesn't mean diddly if your ammo won't back it up.

If you want to stick with factory, try every reasonable round and go with what shoots best in your individual rifle. But at that range, going to handloading is really a necessity. While you can go to extremes with it, learning what you need to for what you want to do is pretty basic.