For Steel or GSSF loads a 3 or 4 port comp works well. For USPSA 9 major I run a SJC 7 port on Glocks, Bedell on my 2011. Running a comp takes a bit of tayloring the load to run the comp. Running a comp and factory ammo is not the best way to take advantage of what the comp can do. If you run factory get some NATO 9mm and see how it shoots.
Team CARVER Custom
GSSF & NRA Life Member
Steel Challenge, USPSA
PM Black Diamond 538 F&AM
Bamatrooper taught Chuck Norris how to shoot.