First off, not wanting to hyjack a thread or take away from acloco's exciting build, I'll comment on the 223 AI.
Secondly, Verminator2, thanks for the props. I'm glad I got someone else excited about these two calibers. They are performing very very well and are ideal for super long range varminting and winning National 1000yard competitions.
If you're interested in the 6.5 Creedmoor, have a look at this great video:
VIDEO
A video like that, with the ingenuity of Hornady (who helped with the 204), demonstrates just how far we have come in cartridge development.
Acloco, I am positive you will love your scope! I have the 6.5X20 version of your's and absolutely love it. There are many times I wish I had the extra power of the 25, and know you'll like your's. I am planing a rifle just like your's for some long range stuff. I have a 1000yard F-class range only a 30min drive from my home, and want to start competing, but also plan to use the rifle for some long range varminting. I contemplated the 223 AI, among many others.
The 223 AI.
Acloco, I think you will really like the 223 AI. #1, you'll get about 100 to 140 fps more speed with any given bullet. Also, the extra case capasity will alow you to push some heavier bullets. I see you're interested in the 75gr V-max. With the 75gr V-max you're looking at around 2900fps.
Here are two loads:
N140 25.5. CCI BR4. 75 A-Max. 2938 fps.
IMR 4895 24.5. CCI BR4. 75 A-Max. 2911 fps.
Secondly, 223 AI brass is extremely stable. Once properly fireformed and trimed to length, you'll have very little trimming to do. The steeper 40degree shoulder resists case growth really well.
Thirdly, you'll get about 2.5 grains more powder per brass. Speaking of brass, 223 should be easy to come by.
That being said, your downsides will be:
Having to fireform brass. The upside is that many people have reported very accurate loads while fireforming, but you're still burning powder and copper to get where you want to be. If you think of it this way, top of the line Lapua brass in the caliber of your choice is still chaeaper than brass, powder, and bullets needed to fireform.
Case capacity is still only somewhere between 24 to 29 grains. Most 204's are shooting about 27 grains. Heavier 50gr and 75gr V-Max's are only behind about 24/25 grains of powder in a 223 AI. This gives only 2900 to 3300 fps velocities. My 204 is shooting 35gr's at over 3700 fps, but admitidely do fade out over 600yards because of low BC bullets. Do the math, a 75gr bullet out of a 223 AI leaves the muzzel at 2900 fps, that is going pretty slow at 600, and real slow at 1000. At 800 and 1000 yards a plain old 243Win way outperforms a 223 AI. The difference between a 223 and an Ackley improved is only 2.5 grains, that's almost insignificant.
Verminator2, I'm with you. The 6.5x47 is just perfect, I am building one. It performs even better than a 243 and even a 308 with way less powder and recoil. Mind you, it was developed to be the King-Pin of long range shooting, and is winning everything. Lots and Lots of testing went in to designing the ultimate 1000 yard cartridge. Below is a very rare photo of two 6.5x47's with both a large primer and a small primer... Awsome. The small primers shot better and that is what is being produced today.
Don't build a 6.5x284, major barrel burners, major. My buddy is shooting one, I saw with my own eyes some very impressive groups at 500 yards. He's at 700 rounds and has already seen his groups open up, even at 100 yards.
Acloco, if your barrel is a 1:7, be prepared to shoot the new 90 grain Sierra's and 90 grain Berger's. A 1:8 shoots the 77gr Sierra MatchKing's nice and the 80 grain MatchKing's. A 1:9 twist shoots mid-range (300-600yards) bullets nice like 69gr Lapua Scenar (.321 BC), 75 A-Max (.435 BC), and Berger 75gr VLD (.447 BC).
Here is your selection of Hornady bullets:
Here is your selection of Sierra bullets:
This velocity table might help you, it's for a 223 and not an AI, but it's almost the same.
Good luck, have fun, and keep us updated! (with pics)