Revolvers are shockingly inefficient

I was over at Ballistics By The Inch, checking out barrel length data on the .357 Magnum, when I noticed that revolvers lose quite a lot of energy versus non-revolver designs. Remembering that revolver barrels are measured differently than those of fixed-chamber designs (for a .357 Magnum gun, add about 1.65" to the nominal length to compensate for the cylinder), we see a dramatic difference in energy produced between the T/C Encore and the Colt Python:

(Given that the barrel-plus-chamber length of the Python is approximately 7.65", I am estimating a 7.5" barrel for the Encore by averaging the performance from 8" and 7" barrels.)


7.5" T/C Encore

Cor-Bon 110 gr. JHP: 484 m/s, 837 J

Cor-Bon 125 gr. JHP: 554 m/s, 1,244 J

Cor-Bon 140 gr. JHP: 516 m/s, 1,210 J

Cor-Bon 125 gr. DPX: 520 m/s, 1,094 J

Federal 125 gr. JHP: 549 m/s, 1,221 J

Federal 158 gr. JHP: 470 m/s, 1,133 J


6" (actually ~7.65") Colt Python

Cor-Bon 110 gr. JHP: 390 m/s, 541 J (35% lost)

Cor-Bon 125 gr. JHP: 419 m/s, 710 J (43% lost)

Cor-Bon 140 gr. JHP: 362 m/s, 593 J (51% lost)

Cor-Bon 125 gr. DPX: 401 m/s, 650 J (41% lost)

Federal 125 gr. JHP: 420 m/s, 713 J (41% lost)

Federal 158 gr. JHP: 358 m/s, 657 J (42% lost)


Oddly, the 4" S&W loses less energy than the Colt. There are a number of factors that could account for this  (smaller gap, tighter rifling, tighter forcing cone, etc):


5.5" T/C Encore

Cor-Bon 110 gr. JHP: 433 m/s, 667 J

Cor-Bon 125 gr. JHP: 507 m/s, 1043 J

Cor-Bon 140 gr. JHP: 468 m/s, 996 J

Cor-Bon 125 gr. DPX: 488 m/s, 964 J

Federal 125 gr. JHP: 499 m/s, 1008 J

Federal 158 gr. JHP: 433 m/s, 958 J


4" (actually 5.67") S&W 686

Cor-Bon 110 gr. JHP: 409 m/s, 595 J (11% lost)

Cor-Bon 125 gr. JHP: 450 m/s, 821 J (21% lost)

Cor-Bon 140 gr. JHP: 391 m/s, 695 J (30% lost)

Cor-Bon 125 gr. DPX: 438 m/s, 779 J (19% lost)

Federal 125 gr. JHP: 438 m/s, 776 J (23% lost)

Federal 158 gr. JHP: 380 m/s, 739 J (23% lost)


So, in general, you're probably losing somewhere between 20-40% of your energy because of the cylinder gap.

For comparison, here's 9mm Luger from both a 7.5" and 5.5" Encore and a 4.875" barreled Beretta 92FS:


7.5" T/C Encore

Cor-Bon 90 gr. JHP +P: 495 m/s, 717 J

Cor-Bon 115 gr. JHP +P: 443 m/s, 730 J

Cor-Bon 125 gr. JHP +P: 411 m/s, 694 J

Cor-Bon 115 gr. DPX: 414 m/s, 639 J

Federal 115 gr. JHP: 375 m/s, 523 J

Federal 124 gr. Hydra-Shok JHP: 357 m/s, 512 J

Federal 147 gr. Hydra-Shok JHP: 318 m/s, 482 J


5.5" T/C Encore

Cor-Bon 90 gr. JHP +P: 473 m/s, 653 J

Cor-Bon 115 gr. JHP +P: 423 m/s, 666 J

Cor-Bon 125 gr. JHP +P: 395 m/s, 633 J

Cor-Bon 115 gr. DPX: 404 m/s, 607 J

Federal 115 gr. JHP: 359 m/s, 480 J

Federal 124 gr. Hydra-Shok JHP: 342 m/s, 471 J

Federal 147 gr. Hydra-Shok JHP: 311 m/s, 459 J


4.875" Beretta 92FS

Cor-Bon 90 gr. JHP +P: 464 m/s, 628 J

Cor-Bon 115 gr. JHP +P: 422 m/s, 663 J

Cor-Bon 125 gr. JHP +P: 394 m/s, 628 J

Cor-Bon 115 gr. DPX: 390 m/s, 568 J

Federal 115 gr. JHP: 343 m/s, 438 J

Federal 124 gr. Hydra-Shok JHP: 340 m/s, 464 J

Federal 147 gr. Hydra-Shok JHP: 302 m/s, 433 J


9mm +P is hot stuff, producing around 80% of the energy of .357 Magnum as fired from a revolver. Most modern 9mm handguns are fine with shooting a steady diet of +P ammunition, in fact more so than some .357 Magnum revolvers are with shooting factory magnum ammunition.