Brian,
5 miles if you're really lucky. As far as being heard but not hearing (sounds like marriage), its probably in your antenna. If your firestik is mounted to an ARB, then ground may be an issue because the powder coat makes it hard to get a ground. This will show up in your swr reading. The solution is easy, just run a wire from the underside of your antenna to one of the holes in your frame and secure it with a bolt.
If its not your antenna, it could be you are transmitting on one channel and receiving on another.
Finally, something to consider . . . amateur radio license. Super easy, loads of power, cheap radios covering all sorts of bands. $10, easy test.
I know our answer has usually been that its not needed since we hang together on the trail, but I can recall the last trip to Cullowhee when we were all sitting around the fire friday night. LandTank was spinning yarns and drinking YaegerMeister, JP was making a duct tape sculpture, and Steve was planning a small revolution in his subdivision.
Meanwhile our hero, Marshall, was leading the really late crew to the Friday campsite. He was lost somewhere between Pettycoat Junction and Hooterville. We could hear him on the FRS radio (being received through a little more powerful handheld), but we couldn't communicate back with him to guide him in. SO, we were having a good time listening and drinking beer! FRS just isn't that strong. Had we all been on HAM, communications would have been a breeze.
Also, HAM is good just in case the worst happens inasmuch as we could get real help faster if someone was in real trouble (read here heart attack). Little cell coverage in holy land, Tellico, etc. Hit the repeater, declare emergency traffic, and the MAMA Copter from Asheville could be there in 20 minutes . . . . As I get older I think about these things.