I plink with Winchester 115g FMj. I can get it around here for 6.99 a box (Wal-Mart). Your P7 shouldn't need any "break-in," or at least that has been my experience. I have several and they have never malfunctioned(on any bullet not made by myself[see below]). Still, I guess you'll want to run it a while before you trust it. I have a Glock 23 that seemed to be working fine up untill I started trusting it. I have had three jams with it (two in the same mag, one later with a different brand of ammo(couldn't tell about the mag though)).
For carry I think you should probably go with the ol' Cor-Bon 115g. It's a proven manstopper and easily availible in most areas. I have shot zillions of rounds of CB through my P7's without a hitch.
You might want to consider reloads if you can get em' cheap. The only thing to worry about with reloads is keeping a close eye on the cleaning of the gun. When I shoot a bunch of reloads I just go-ahead and give it a stick with the cylinder tool and a brush with the cylinder brush. I once shot a crapload of my own personal (and muy bad) reloads through my old M13 without cleaning. After (my guess) about 3k the slide started sticking back after the gun was shot 100+ times in a sitting (the slide would stick back after the final round was fired and you tried to release it with the cocking lever). All I had to do to solve the problem was do the 500 round cleaning procedure (tool and brush) and everything was fine. Also, the gun never jammed after this abuse (if you wanted to keep shooting you just had to put a new mag in and tap on the slide with your hand). I cannot say that for my old Sig 228 and HK P9. Both of them jammed around 5-800 rounds. In their defense, my reloads were CRAPPY (overcharged, undercharged, 2-4x reloaded case!, lax bullet depth, etc).
GHB
[This message has been edited by Greg Bell (edited October 29, 1999).]