For only 300 yds. it'd probably help to have a simple ballistic reticle, so with that in mind, i'd go for a lower-medium powered scope with a simple plex reticle that the lower post goes down to about 1.5-2.5 MOA below the x-hair (at the scope's highest power), for the simplest ballistic/ranging reticle system around. It's fast, easy, and just as effective as any other ballistic reticle with a little practice, and probably a little cheaper than a ballistic reticle.
My 4-12X Burris Compact nets me 2.7 MOA to the plex reticle's lower post tip at 12X, and gets me to 350 yds. trajectory compensation with my rig. It helps to research tactical apps. tho with scope reticles, but once understood with a decent laser 300 yd. shots are a cinch in good conditions when game gives u some time to apply the system.