I run a plain old .243 and love it. My problem is my factory barrel has a 1-9 1/8 twist so it won't stabilize 105s. I shoot 87gr V-MAXs in it and its a ton of fun. Really have to read the wind because that little slug gets pushed around a ton out there at longer ranges. If I can reliably read the wind and put accurate groups and hits down range with it, then shooting my new .300 will be much easier with my experience and knowledge I gained with the .243! It's a great rifle to practice with, easy to load for, accurate, low recoil, and just tons of fun. Also plays hell on ground hogs and birds haha!
The .260 or .260 AI is another great option as well. I plan on either rebarreling my .243 or building a .260 because I have recently discovered just how great this cartridge is! A 140gr A-MAX with a .585 BC or a 140gr Berger Hunting VLD with a BC of .612 is amazing. With the 140 you can easily get 2800fps with the standard .260 and 2900+ with the Ackley version. This combo outperforms the .243 and .308 with recoil just slightly more than a .243 but with more knock down than a .308 at long range! Just an all around great cartridge!
