I am looking at building my first custom. What i have come up with after countless hours behind the keyboard and reloading manuals is a 280 ackley imp. This will be my go to gun for medium to large size game out to 700 or so yards. My plans are remington 700 action (or clone like the borden timberline), brux ss barrel finished at about 27-28 in, manners mcs-t stock. I want to shoot berger 168 vld at about 2900fps. Is that speed possible? Is a custom action worth it or should i just have a 700 blueprinted? Is there an other caliber worth looking at? Let me know what you guys think.