Empty Clips or Piercing Rounds

If you were a Dual Pistols character and had to choose between one of these two powers, which would you take?

First of all, why are you trying to decide between them? They both are handy to have. Piercing Rounds may be a narrow cone, but you can still leverage it. Plus it's some pretty good damage. And you'll probably want Empty Clips since it's a cone attack.

both. that is why i have my dp paired with energy melee. i only needed like 4 powers from energy melee and took everything from dp.

Well, I only have room for six DP powers in my Defender's build. Pistols is mandatory, so I figured Pistols, Dual Wield, Bullet Rain, Swap Ammo, Supression Fire for the hold, and either Empty Clips or Piercing Rounds.

O.o what primary? Many primaries have one or two powers you can skip. And if it doesn't have toggle powers, you may not actually need stamina. Assuming 2 powers to get a travel power, if you can do without stamina then you can easily take everything from primary and secondary. Similarly your epic pool may have a power or two you don't want.

If I absolutely had to choose: empty clips.

If you have to choose then Empty Clips but as others have said it's well worth looking at getting both.

Dual Pistols for Defenders (and Corruptors) is always going to be a tight build. Most blast sets need 4 or 5 powers to give you a decent attack chain and the rest is optional depending on your primary and personal inclinations. Dual Pistols has that but also has two very useful debuffs (Swap Ammo and Piercing Rounds) a hold instead of a stun and a crashless nuke meaning you really want 7-9 powers instead of 4-8 for other sets. So realistically if you're doing Dual Pistols on a defender or corruptor you really want a primary where you can easily skip two or three powers and are probably not going to have room for leadership powers (essentially you're trading leadership buffs for better debuffing through your secondary).

Empty Clips is a pretty crappy cone unless you pair it with /Energy (Boost Range does nice things to short-range cones). Boost Range also has the nice side effect of making Piercing Rounds easier to use, so I'd go with PR in a flash.

I'd say drop suppression fire (I've had 4 DP characters, none of 'em have ever gotten much out of it) and get both piercing and empty clips. The thing to remember with piercing rounds is that it's only a little bit less damage than executioner's shot (your big ST hitter) and does it at 80' range to potentially multiple people, in addition to adding a tasty -res if you use stock ammo. Empty clips is kind of junky (I much prefer bullet rain) but it's not a bad cone attack, just sort of there.

9 pool powers being taken then? fitness 3, haste poss 1, travel 1, 4 left hmm, 2 from an epic? 2 leaderships to finish up? My decision on which one to take will probably come from knowing the rest of the build...most likely empty clips.

It's a Force Field / Dual Pistols Defender. From FF, I'm looking at Personal Force Field, the two bubbles, Dispersion Bubble, Force Bolt, Repulsion Bomb, and Force Bubble. Swift, Health, Stamina, Hover, Fly, Maneuvers, Tactics, Assault, and Recall Friend from the power pools. Power Build Up and Temp Invulnerability from Force Mastery. Hrm. Well, I suppose I could skip Tactics, and just slot a Kismet proc in Dispersion Bubble or something.

I'd skip Assault and keep Tactics. I'd also drop Recall Friend.

You can't squeeze in Hail of Bullets? It's like a crashless quasi-nuke.

For soloing, I'd make a second build just for that.

You'll be able to skip a bunch of primary FF stuff on a solo build. Keep PFF, Dispersion Bubble... and take tons of attacks and such.

Swap back to a rounded build that is heavier on the FF set for teaming.

If I had to skip one or the other...

Empty Clips.

Piercing Rounds I find great for teaming against AVs. Switch to Lethal rounds, start firing off the -Resistance, to have the rest of the team do more damage.