Until such day that Science creates the nuclear sidearm
you are pretty much limited by F=MA (the recoil you can handle for one thing) and the amount of weight you are willing to carry. There is no doubt that a longer barrel will add more velocity. Now whether velocity equals lethality, that is something that needs to be tested against an agreed on ballistic media. It has been taken as an article of faith that more velocity equals more lethality. I don't agree on that, but there are limits. Handguns are not that impressive, as compared to maces and pole arms, but they will do the job.
There are definite limitations with 38 Special revolvers, but they are, what they are
Code:
Colt Detective Special mfgr 1963 24-Jul-99 T = 100 F !
158 gr LRN 3.5 grs Bullseye thrown, CCI primers mixed cases
Average 751 fps
Standard Deviation 32 fps
Extreme Spread 90 fps
High 805
Low 715
Recorded shots 22
158 LRN 3.5 grs Bullseye WSP Mixed cases 8-Jan-06 T = 52 F
Ave Vel =675.9
Std Dev =18.6
ES=96.18
High=723.9
Low=627.7
N =32
158 LSWC 3.5 grs Bullseye WSP Mixed cases 8-Jan-06 T = 58 F
Ave Vel =706.8
Std Dev =15.55
ES=65.87
High=742.9
Low=677
N =32
Code:
Taurus M85 B2UL 2" Barrel
158 LSWC 3.5 grs Bullseye thrown, Mixed Brass WSP 11-Dec-04 T = 54 F
Ave Vel = 686.3
Std Dev = 13.63
ES 58.48
High 718.8
Low 660.3
N = 30
shot little high and centered
158 LRN Master Factory Ammo 30-Dec-04 T = 56 F
Ave Vel = 698.2
Std Dev = 20.56
ES 105.8
High 753.5
Low 647.6
N = 32
shot 6" high centered,until barrel leaded
158 LSWC 3.5 grs Bullseye Mixed brass Fed 100 30-Dec-04 T = 56 F
Ave Vel = 706.2
Std Dev = 23.45
ES 81.94
High 748
Low 666.1
N = 32
Code:
S&W M638-3 Airweight Bodyguard 2" barrel
148 LWC Lead 2.7 grs Bullseye thrown Mixed Brass WSP
18-Mar-07 T = 52 °F
Ave Vel =611.6
Std Dev =22.04
ES=75.92
High=648.1
Low=572.2
N =25
little high
158 LSWC 3.5 grs Bullseye Mixed brass WSP
18-Mar-07 T = 52 °F
Ave Vel =611.1
Std Dev =9.64
ES=28.05
High=626.3
Low=598.3
N =32
4-6" High accurate
Code:
S&W M637-2 2" barrel
158 LRN 3.5 grs Bullseye WSP Mixed cases
6-Apr-07 T = 48 °F
Ave Vel =679
Std Dev =16.48
ES 56.11
High 698.2
Low 642
N = 18
125 Lead BBRNFP 4.0 grs Bullseye Lot BE 532 Mixed cases CCI 500
6-Apr-07 T = 48 °F
Ave Vel =763.9
Std Dev =22
ES78
High806.5
Low728.5
N =15
Point aim OK
125 Lead BBRNFP 4.0 grs Bullseye Mixed cases WSP
9-Apr-06 T = 59 °F
Ave Vel =760.4
Std Dev =27.33
ES =82.1
High =798.9
Low =716.8
N =19
125 Lead BBRNFP 4.5 grs Bullseye Mixed cases WSP
9-Apr-06 T = 64 °F
Ave Vel = 827.9
Std Dev = 23.21
ES = 92.27
High = 879.4
Low = 787.1
N = 20
Code:
4" S&W M10-5
148 LWC Valiant 2.7grs Bullseye W/W cases WSP
19-Apr-09 T ≈ 60-65 ° F
Ave Vel = 696.2
Std Dev = 12.04
ES = 48
High = 721.3
Low = 673.3
N = 32
v accurate, about 2" low, no leading, mild recoil
158 LRN Valiant 3.5grs Bullseye Mixed cases WSP
19-Apr-09 T ≈ 60-65 ° F
Ave Vel = 758
Std Dev = 22.86
ES = 100.9
High = 810.5
Low = 709.5
N = 32
158 LRN 3.5grs Bullseye Mixed cases WSP Gamma Chrony
5-Aug-06 T = 100 °F
Ave Vel = 796
Std Dev = 13.89
ES = 55.24
High = 813
Low = 757.9
N = 23
158 LRN 3.5grs Bullseye Mixed cases WSP
22-Dec-07 T = 52 °F
Ave Vel = 768.6
Std Dev = 15.58
ES = 48.52
High = 787.6
Low = 739.1
N = 18
125 Valiant BBRNFP 4.0 grs Bullseye Mixed cases WSP
9-Apr-06 T = 59 °F
Ave Vel = 863.4
Std Dev = 30
ES = 70.78
High = 907.5
Low = 836.7
N = 6
Windage centered accurate
Elevation at least 4" low
125 Valiant BBRNFP 4.5 grs Bullseye Mixed cases WSP
9-Apr-06 T = 64 °F
Ave Vel = 945.6
Std Dev = 27.28
ES = 75.21
High = 995.2
Low = 920
N = 6
Windage centered accurate
Elevation at least 4" low
If you are man enough, have the pocket space, and want the power, how about packing a cannon?
Go retro!
that's the barrel weight, the carrage adds a bit more
Or, the modern and sleek, 5 incher
might need something to put under it, may I suggest a Fletcher Class destroyer?