Funny you should bring this up, I just recently posted a 'Ten Tips for Indie Actors' and the number 9 tip was all about making recoil look real.
Let me just post the tip for ya, if you don't mind.
9. Know your Firearms
Something that plagues indie sets are the ill-use of firearms. It is your job as an actor to make it believable that you are firing a weapon that uses real bullets—this means the kick (or recoil) should resemble the real-world affair. Study how big-budget actors handle their firearms. Hell, you’re an actor…it might be worth it to go out and fire a few weapons for real. Watch the recoil…how it manipulates your wrist first, then forearm. Understand different caliber weapons produce stronger kicks. Realize your eyes may inevitably close during a shot (unless the director specifically tells you not to). I can’t explain exactly how to make it look great without actually showing you…so I leave it up to you to realize its importance. And for goodness sake, don’t mouth the sound of the gun…believe me, a lot of actors do it, even if it’s super subtle the camera will pick it up.
So basically. It's up to your actors to make it look real. The way I look at it DRThunder is like this...at least you care. At least you want to make an effort to make it look convincing. That is the first step, and as long as you care, the recoil will look just fine.
Before you actually shoot anything (double pun), make sure you work with the actors and the firearms.
Take a look at this video:
http://www.youtube.com/watch?v=h2Sh_c3QrAw
They are using an air cartridge...that is a good substitute for gunpowder, and will create very realistic kick.
Hope I've helped. Have a great weekend.