That's often mentioned as some kind of advantage to the flint guns but truth be known unless you're in very specific geographical regions of the U.S. you are going to have a tough time finding anything that will spark well, AND THEN you have to know how to knap them.
I'll bet 95% of those repeating "you can find flint just laying on the ground to keep the rifle going!" A) would not be able to identify let alone locate appropriate rock to make flints and B) know how to knap them properly to make said flint.
I'll bet 95% of those repeating "you can find flint just laying on the ground to keep the rifle going!" A) would not be able to identify let alone locate appropriate rock to make flints and B) know how to knap them properly to make said flint.