Yes, the CZ 527 Carbine is a sweet rifle... the 7.62 x 39 cartridge is very similar to 30-30 but about 1/4th the price... think $5 / 20 rds vs $15-$20 /20rds. The CZ might be a little bit TOO nice for the task at hand... sounds like you're going to get this thing dirty. That CZ, while no doubt reliable, is a little too pricy for mucking about. I'd just get an SKS, probably. They're $200-300, reliable, and semi auto as well. Also, they are the cheapest and most practical gun I can think of that I'd want to take a cow out with from 7 yards... and not as Noisy and overkill as a Mosin or some other full powered rifle.
Otherise, a .357 or .44 mag revolver might work well if you're thinking handgun. Probably a ruger gp-100 or Redhawk. If I was going to shoot a cow, I'd personally use a long gun... but I'm not an experienced pro cow killer. The Marlin 1894 in 357 or .44 would save you a lot of money on ammo too (vs the 30/30), assuming you're not reloading yourself. I personally am a reloader, so a 336 in 30-30 is going to be my next farm gun.