Previously Covered

In the pocket guns I've carried...

For GURPS of course.

My first pocket carry gun was an FIE Titan in .25 ACP.  Then a Colt Junior, also in .25 ACP.

They both do 1d pi- damage with a Rcl of 2.

My next pocket carry was a Colt model 1908 Pocket Hammerless in .380 ACP.

2d pi, Rcl 2.

Then I alternated between a S&W 640 in .357 Magnum and a SIG-Sauer P238 in .380 ACP.

2d+2 pi, Rcl 5 for Magnum.
2d-1 pi, Rcl 2 for .380 ACP.

Since I use state of the art hollow-point bullets pi- becomes pi and pi becomes pi+ and all of them get the (0.5) armor divisor.

In order...
.25 ACP -- 1d(0.5) pi
.380 ACP -- 2d(0.5) pi+
.357 Magnum -- 2d+2(0.5) pi+
.380 ACP -- 2d-1(0.5) pi+

Against a torso with the HPs that's...

.25 ACP -- 1-5 (avg 2)
.380 ACP -- 1-16 (avg 9)
.357 Magnum -- 4-19 (avg 12)
.380 ACP -- 1-15 (avg 7)

Magnum seems the clear winner!  But, with that Rcl of 5, you need some amazing rolls to land two hits, let alone all three the RoF normally allows.

Using the classic self defense range of 7 yards, that gives a -3 to skill.  The double action only nature of the revolver gives an additional -1 to skill as well.

The average DX 10 person with 1 point in the DX/E skill Guns/TL8 (Pistol) has a skill of 10.  Every point of skill is loosely representative of 200 hours of training/practice.  Yes, most people will be rolling the default of DX-4 or 6.

At the range, we get a +10 to our skill to represent that combat is much more stressful than just standing there with no danger of the paper shooting back.

So...
At the default level it's 6 for skill, +10 for no stress controlled environment, -3 for range and maybe -1 for double action.  13 or 12 without aiming depending on the gun.

With the autos you have a 83.79% to hit with one shot, 62.50% chance to hit with two and 37.50% to hit with the entire RoF 3 into a rather generous 18" diameter circle.

With the revolver things get much harder.  74.07% chance to hit with one shot, 16.20% chance to hit with two shots and no chance at all to hit with all three.

Twice as likely to hit with all three rounds from the autos as with two from the magnum!  The average roll of 10 on 3d6 means that, on average, two hits for an auto and one for the revolver.

Again, in order...
.25 ACP -- 2 hits, 2-10 (avg 4)
.380 ACP -- 2 hits, 2-32 (avg 18)
.357 Magnum -- 1 hit, 4-19 (avg 12)
.380 ACP -- 2 hits, 2-30 (avg 14)

In combat, losing the +10 bonus really starts to hurt.  6 for skill, -3 for range and -1 for double action if applicable.  You need to roll a 3 or less to even land a single with an auto without aiming and technically get no roll with the revolver.  All out attack (determined) might be a worth it to get the +1, but it merely makes it possible to hit at all with the revolver and doesn't much improve the odds with the autos.  On average, you miss with all three.

The amount of training that one receives in the Army is sufficient to earn a point in the skill.  This greatly improves your odds!  Part of training is to learn to use both hands to fire a handgun, but this isn't assumed in the rules but it's another +1.

At the range:
Skill 10, +10 for no-stress, +1 for two handed stance, -3 for range, -1 for double if applicable.  18 or 17... or:

With the autos you have a 100% to hit with one shot (actually 99.53% because a roll of 18 with this skill level is a critical failure), 98.14% chance to hit with two and 90.74% to hit with the entire RoF 3 into a rather generous 18" diameter circle.  On average, you do land all three!

With the revolver things are still harder.  99.53% chance to hit with one shot, 74.07% chance to hit with two shots and 16.20% to hit with all three.  On average, you hit with two.

Again, in order...
.25 ACP -- 3 hits, 3-15 (avg 6)
.380 ACP -- 3 hits, 3-48 (avg 27)
.357 Magnum -- 2 hits, 8-38 (avg 24)
.380 ACP -- 3 hits, 3-45 (avg 21)

In combat:
Skill 10, +1 for two handed, -3 for range and -1 for double action.  7 or 6.

The autos get a 16.20% chance of one hit, 4.52% of two and a mere 0.46% for all three.

The revolver gets 9.25% to hit once and is mathematically eliminated from hitting more than that.

This is the average schmoe...  You will never see a player character with skills this low!  DX of 12 and 4 points in the skill raises base skill to 14!  +4 is a significant improvement in your odds!

The autos get a 74.07% chance of one hit, 50% of two and a 25.92% for all three; or two hits on average

The revolver gets 62.50% to hit once, 9.25% to hit twice and is mathematically eliminated from hitting three time; or one hit on average.

In a pistol fight, it's probably worth the +1 for All-Out-Attack (Determined)

The autos get a 83.79% chance of one hit, 62.50% of two and a 37.50% for all three.  (Two hits on average.)

The revolver gets 74.07% to hit once, 16.20% to hit twice and is still mathematically eliminated from hitting three time; or one hit on average.

The autos have pathetic accuracy, Acc 1, but the revolver gets Acc 2.  Getting a second to aim as your assailant is approaching ups the odds to...  Skill 14, +1 or 2 for Acc, +1 for two-handed, +1 for All-Out Attack, -3 for range and -1 for double action.  14 for everyone!

The autos get a 90.74% chance of one hit, 74.07% of two and a 50% for all three; or three hits on average!

The revolver gets 90.74% to hit once, 37.50% to hit twice and 1.85% to hit three times; or still one hit on average.

Once again, in order...
.25 ACP -- 3 hits, 3-15 (avg 6)
.380 ACP -- 3 hits, 3-48 (avg 27)
.357 Magnum -- 1 hit, 4-19 (avg 12)
.380 ACP -- 3 hits, 3-45 (avg 21)

Kind of sours you on pocketing a snubby .357 don't it?