What rifles just aren't picky about ammo?

[Phillz]

I've always thought it was cool how some rifles can shoot pretty much any ammo, while others are super picky. From your own experience, what rifles or models seem to handle different kinds of ammo. If you've ever had a rifle surprise you by working perfectly with questionable ammo, I'd love to hear about it.

 

[Hawked]

My old Ruger will eat anything I give it... even the ancient ammo I found in the back of the closet

 

[Quark]

That a single shot bolt action rifle is very picky about any .223 Remington that has government primers.