If ammo weren't so (insert expletive), expensive, I might get the .357 Sig barrel for my full size .40 M+P. The mags will shoot both rounds.
Power
The 38 Super ranks as one of the more powerful “common” semi-automatic pistol cartridges. (See Table 1. Data is from the manufacturer’s published ballistics and is based on generic ammo typical of that cartridge. Published velocities for a given cartridge vary between manufacturers). With a muzzle energy (ME) of 426 foot pounds, the Super’s sheer power is exceeded only by the 357 Sig, 9X23 Winchester and 10mm. The 38 Super surpasses its larger caliber allies, the 40 S&W and 45 ACP, in raw energy.
38 Super vs 9mm
Inevitably there is a comparison between the 38 Super and the 9mm Luger. The Super has a clear advantage, though it is not a huge advantage. The Super propels a 130 grain bullet about 25 fps faster than the 9mm propels a 115 grain bullet. That translates into a roughly 60 ft. lbs. M.E. advantage (about 15%) for the 38 Super. Whether that difference is meaningful or not is a matter of opinion, with 38 Super lovers voting Yes, and 9mm lovers voting No. Like many things in life, we view things in a light that favors our preference. Still, the math places the 38 Super ahead of the 9mm.
9mm +P loads do approach the Super’s power level. But the 9mm +P is loaded to higher pressures than the 38 Super. The SAAMI maximum average pressure for the standard 9mm Luger is 35,000 psi. The 9mm Luger +P maximum is 38,500 psi. The 38 Super SAAMI maximum average pressure is 36,500. Some of you readers are protesting because today’s 38 Super has the designation of 38 Super +P. That’s right. But remember that the +P name designation was added in 1974 solely to distinguish it from the old 38 Automatic, not because the Super was suddenly loaded to higher pressures in 1974. It was a “bureaucratic” name change only, not an actual change in pressure. So, in fact, the 38 Super +P is still the standard pressure 38 Super just as it was when created back in 1929. If the 38 Super was loaded to an increased (real) +P pressure designation it would be much higher than the 9mm +P. For example, the +P designation added 3,500 psi onto the standard 9mm SAAMI maximum. Doing the same to the 38 Super would result in a SAAMI maximum average pressure of 40,000 psi. That would boost velocity and power significantly, well beyond the 9mm +P, and even beyond the 9mm +P+.
The ballistics of 9mm +P+ ammunition are in line with, and slightly exceed, the ballistics of the standard factory 38 Super (Table 3). Winchester’s 127 grain Ranger +P+ produces 441 ft. lbs. M.E. Remington’s 115 JHP +P+ produces 438 ft. lbs. M.E. Remember that the 38 Super’s standard 130 grain FMJ produces 426 ft. lbs. M.E. Higher pressure loads (real +P or +P+ pressures) in the Super would easily surpass 500 ft. lbs. M.E. and would be close to the 9X23 Winchester. By the way, the 9X23 can be loaded to at least 46,000 psi (Winchester’s 15th Edition Reloader’s Manual) which explains why it has such impressive performance and makes it one of the highest pressure handgun cartridges around.
http://38super.net/Pages/comparisons.htmlLOTS more info at link. great charts also.
Great round, alas, like the .41 Magnum, and/or 10mm.....It comes down to AMMO availability, or reloading.