Only one...

[AK103K]

This cartridge can do ANYTHING out to maybe 125 yards.

On top of that, I could do everything with just these three guns:

But it cant do it at 800-1200 RPM

This one can do it all, and all by itself. Hose'em up close, and head shots at 125 yards.

 

[Deja vu]

.357 Magnum easily. A revolver chambered for this cartridge is capable of many tasks from plinking with .38's to hunting of deer-sized game with heavy magnums. I can have revolver ranging in size from small lightweight models like the S&W 360 and Ruger LCR all the way up to large-frame hunting guns like an S&W M27 or Ruger Blackhawk with a semi-auto like a Coonan or Desert Eagle as well as a good rifle like a Marlin Model 1894 thrown in as well.

I love the 357 magnum.

it is the only Caliber (that I know of) that can be found in pocket pistols, Derringers, full sized revolver, Semiautomatics, lever action rifles and now in bolt action rifles (Ruger 77/357)

 

[Hagar the Republican]

I'm going with .357 as well.

So far we have:

.357 mag. in the lead with 31 votes.
9mm w/12.
.45 ACP w/10.
.22 w/.4
.44 mag. w/3
.45 Colt w/2
.40 w/2
460 w/1
10mm w/1
475 w/1

The votes were disqualified when they couldn't make up their minds and listed two or three.

 

[NightSleeper]

.40 S&W

 

[Sgt01]

9mm. Easy to find, inexpensive and fairly accurate. Add a Glock 19 to that and I'm good to go.

 

[praetorian97]

Seems like 357 is going strong but are you guys talking magnum or sig???

 

[Hagar the Republican]

The real deal - magnum.

 

[MLeake]

Agree with .44 magnum, as a handloader can run anything from mild .44 Special to heavy carbine loads.

 

[TylerD45ACP]

45 ACP but the 9mm is a close second. I love both these rounds just the 45 a little more .

 

[357 Terms]

The 4inch 357 mag. Nothing else compares to the versatility and performance of this package. Add a snubby and a lever action and you have all your needs covered with one caliber.

 

[spodwo]

.357 Magnum.

 

[Nanuk]

357

 

[C0untZer0]

9mm IMO is the most versatile. I can run it in a compact like a Kahr PM9 / Rohrbaugh R9 / Diamondback DB9, I can run it in full sized pistols, I can run it in a MAC or MP5, or a carbine like the Marlin Camp 9. Really versatile.

If you think ammo prices are high now - wait until the apocolypse !

Most people will not be selling their ammo, and those that do will be selling a box of ammo for like $1,000 worth of food and medicine.

There should be a lot of 9mm NATO around - compared to things like .44magnum and such. I think there will be more 9mm ammo around than .40 S&W.

So if I can have only one - it would be 9mm

 

[Carry_24/7]

.45 ACP

As companion, I'll take the UMP 45.