Damn, I'm short a rifle. What would you recommend?
Anything you can afford and afford to feed. Practice is very important. Surplus bolt action rifles can be gotten for as little as $100 and there is still surplus ammo available reasonably cheap.
If you have the money and don’t live in a communist state, a semi-auto in 5.56x45, 7.62x39 or 7.62x51.
Ruger mini 30, AK variant or an AR variant. Ruger has a very nice AR556 that I’ve seen as low as $535
Of course, if you want to go really cheap and maybe mate a pistol cartridge to a rifle (giving you better accuracy and range and an increase in stopping power over your pistol), here is another good choice. Add a few extra mags for $25 and you are in business for even less than the bolt action, above.
Your local gun store probably has similar offerings. There are a lot of very useable rifles out there right now at a good price that won't break the bank.
I (don’t) have a Ruger Redhawk. I (also don’t) have an NAA minirevolver. I (also never) purchased an AR. And I (would never be caught dead) possessing a Glock.