Most people will agree the 38 is a better performer. I agree with that, many will also throw wild unsubstantiated numbers out, which I think is amusing. Most opinions, which is what you will get for answers, including my own opinion, are just that with no scientific data, which is why I suggest you go to ballistics by the inch (ballisticsbytheinch.com) and look at real world test results, (velocity) from real world weapons, including the 1.875" barrel snubs and the 2.75 LCP. If you are looking solely at energy which you seem to state in your original post, take the velocities and bullet weights from ballistics by the inch and go to
Muzzle Energy Calculator and plug in the numbers. Then you have the energy graphs from muzzle out. It gets a little interesting then.
Example
380acp test results out of a LCP
Speer Gold Dot 90gr-918fps = 168.4ft-lbs muzzle energy
Corbon 80gr DPX-849fps = 144.03ft-lbs energy
Buffalo Bore 90gr JHP+P-1054fps = 221.99ft-lbs energy
38 special out of 1.875 inch S&W 642
Speer Gold Dot 135gr-897fps = 160.78ft-lbs muzzle energy
Corbon 110gr DPX-961fps = 184.54
Buffalo Bore 110gr JHP+P-1104fps = 243.55ft-lbs muzzle energy (Buffalo Bore fps from their site [1.875" barrel] as ballistics by the inch hasn't tested Buffalo bore for 38)
As you can see, if you look solely at energy there is not as big a difference as one might expect. Is 20-40 ft-lbs a lot? That is a subjective question. And many will lean toward the 38spl is better due to the heavier bullet loads, but looking solely at energy as the weight increase the velocity decreases, to the point of diminishing returns, and energy drops off quickly. Now, is the 38 special, especially +P, a better overall "performer" than a 380acp from an energy stand point, yes. But the fact is a 38spl was designed for 4 inch + barrels and therefore starting at 4 inch barrels on up you begin to really see the gains over the 380acp that you would expect.
Just a note, I have an LCP, and 4 1.875 inch S&W's, and one Taurus 38spl snub. I see no difference regardless of which (LCP vs snub) I carry, it is really tomatoes-tomotoes to me. So, IMHO, unless you just want a LCR (which are great guns and that is enough reason :image035
, I don't think you will be getting the "step up" you desire. Now, for a wheel gun, a Ruger SP101 357Mag with a 3" barrel stoked with Buffalo Bore 125gr JHP-1476fps = 435.33ft-lbs muzzle energy (513.47ft-lbs from a 4"), may be more what you are looking for as an upgrade..........:wink: