Pocket Revolver

This is a GURPS post, so real life could be significantly different.

S&W has made a five shot .357 Magnum J-Frame for a long, long time.

With magnum ammo it does 2d+2 pi out to 180/2,000 with ST 10 and Rcl 5.

With a moderate skill level, you're just not hitting with a second shot and you can fire 3 per round.

Colt is releasing a new version of the Detective Special Cobra in stainless that's rated for +P ammo.

.38 Special from a 2" barrel normally gets 2d-1 pi to 90/1,000 with ST 8 and Rcl 2.  You're much more likely to get multiple hits with the same skill level than with a magnum.

But what about the +P?  That's as good as a magnum, right?

GURPS High-Tech p. 165 gives a 10% bonus to damage and range and increases the ST by the same margin.

That ups the damage to 2d pi to 100/1,100 with ST 9 and Rcl 2.

Now...

Guns/TL is a DX/E skill with a default of DX-4 or another Guns/TL skill at -2.  The average person has a ST and DX of 10.

A point in any given skill is the equivalent of 200 hours of study on their own figuring it out for themselves.  What this means is the average person has a skill level of Guns/TL8 (Pistol) of 6.  With the +10 to your skill for being at the range, you can see how someone can quickly think they've got adequate skills.

But let's assume our shooter is an avid study and has put 2 points into it to get a Guns/TL8 (Pistol)-11.

At the, ever popular, 7-yards there's a -3 range penalty.

With the Magnum, we're going to have an 8 to hit and if we fire the full three rounds we'd need to roll a 3 to hit with the second shot and there's no way the third is connecting.

With +P we start with the same 8 to hit, but our second and third shots will hit on a roll of 6 and 4 respectively.

We're within a whisker of having the same chance of hitting with three rounds of +P as two of Magnum.

Just to boil that down a tad.

8 or less is a 25.926% chance.
6 or less is a 9.259% chance.
4 or less is a 1.852% chance.
3 or less is a 0.463% chance.

The guy missing with all five shots firing over the counter at the convenience store makes more sense now, doesn't it?  That's at a whopping 1 yard.  No penalty to hit for range!

Now the magnum hits one round on a 11, two on a 6 and still can't land a third on a 1.  +P will hit the first shot on the same 11, second on a 9 and third on a 7.

11 or less is a 62.500% chance.
9 or less is a 37.500% chance.
7 or less is a 16.204% chance.
6 or less is a 9.259% chance.

Did I mention that three 6-sided dice average a roll of 10?  On average nobody hits at all at 7 yards!

But let's check damage anyways.

Assuming that hollow points change the damage to 2d+2(0.5) pi+ for Magnum and 2d(0.5) pi+ for +P...

Average damage for the Magnum against an assailant in a t-shirt is 12 per shot (4 to 19 spread).
Average damage for the +P is 9 per shot (1 to 16 spread).

Potentially, the +P can land more damage than the Magnum just because it's possible to get all three rounds to hit.  +P is also going to do more damage because it's far more likely to get a second shot to hit.

Of course, no self respecting adventurer is going to have such a low DX or skill...