You need not even get as exotic as the Coonan. The .357 Sig, which is essentially a .40 S&W case bottle-necked to .357 has ballistics that compare favorably with full horsepower .357 magnum rounds. Here are a list of LE agencies who have chosen the .357 Sig as their round of choice:
Alameda County
Delaware State Police (First to adopt the 357 SIG)
Dallas, Texas Police
Federal Air Marshals
Federal Protective Services (FPS) Special Agents for General Services Administration (GSA) - P229
Keizer Police Department, Oregon
La Porte County Indiana Sheriff's Department
Laurence County Sheriff's Office, Tennessee
Las Vegas Metro Police (allowed use of)
Liberty Twp Police Dept, Ohio
Maine Aroostook County Sheriff's Office
Maine Game Wardens (P226)
Maricopa County [Phoenix] Arizona Sheriff's Office/MCSO
Montcalm County (Michigan) Sheriff's Office
New Jersey Division of Fish & Game
New Mexico State Police
Niles Police Dept, Ohio
Northwood Police Dept, ND
NC Highway Patrol
NC Wake County Sheriff's Department
NC Wildlife Enforcement Officers
Nueces County Sheriff Department, Texas (Sigpro)
Oakland County Sheriff's Dept, Michigan
Orange Police Dept, CT (sig pro, SP2340 .357)
Orlando PD (plainclothes officers)
Oxford, Mississippi
Richmond, Virginia
Rocky Mount Police Dept, Rocky Mount, NC
Springfield, IL
Tennessee Highway Patrol
Union County Sheriff's Office, Marysville, Ohio (Glock 31)
Texas, DPS
United States (GSA) - Office of Inspector General (OIG)
Special Agents - P229
United States Secret Service
Virginia State Police
It's like the V6 vs V8 argument. A bigger block will ALWAYS produce more horsepower. No matter how you try to tart up the smaller motor.
Size and speed count in the ballistics world. More of one at the expense of the other will not have the results of one that has a good balance of BOTH.