I have a Rem 700 30-06 that has a barrel that I believe has seen its better days. I am left with a good long action that I would like to build off of, but am having a hard time deciding on a good caliber. For the most part I would like it to be effective at moderate (300-400) yards on medium sized game, and accurate for those long range targets and varmints. I would be willing to listen to as many different opinions as possible.
Well if you do not want another 30/06 then I would go with a 6.5-284. They shoot flat buck the wind and hold enough energy for what you want to shoot with it. They also have mild recoil and do not use a lot of powder.
I would agree with all the calibers listed but I would have to go against the currect traditional opinion on which caliber to use.
For the receiver you have, I would recommed one of two rounds, either the 6.5-06 AI or the 280 AI.
Simply because they pose zero feeding issues at all with your receiver and would nearly match the ballsitic performance of the WSM rounds and are a fair bit over the 284 wildcats.
Again, current opinions on case design will tell you that teh short fat cases are the most accurate. On paper that may be true but in quality rifles, they all shoot EXTREMELY well.
For your needs, I would recommend the 6.5-06 AI using the 100 gr Ballistic Tips or 95 gr V-Max bullets for moderate range varminting, the 120 gr bullets for deer size game out to 400 yards and the 140 A-Max and 142 gr Wildcat ULD for long range shooting.
The 6.5-06 AI will drive a 140 gr bullet to well over 3000 fps in a 26" barrel which is plenty for extreme range shooting consistancy.
Cheap to load, easy to build, feeds like a dream and will offer 1/4 moa consistancy with top loads.
This would be my pick for a project like yours.
Allen Precision Shooting
Home of the Allen Magnum, Allen Xpress and Allen Tactical Wildcats and the Painkiller Muzzle brakes.
6mm-06 is a wonderful round. That way you can also use your brass. You probably have to neck then to 25-06 first step. The 100 grain bullets in the 3300 fps range would have mild recoil and very deadly on small animals.
.270 Ackley improved 29 inch 1.250 dia. target barrel 7mm STW 28 inch 1.250 target barrel. I also love my .458 mag for varmints and the biggest game in the world.