How Does .38 Super Compare to 9mm? Of late I see this question being asked more and more frequently rather than the perpetual 9mm vs. .45 ACP debates and questions.  The general consensus seems to be that the .38 Super is a more potent round than the 9x19mm, 9mm Luger, 9mm Parabellum,, or whatever moniker is being used for our current military pistol round. I think it's a pretty interesting question and one that might have some unexpected answers.



Flanked by .38 Super rounds, the difference in physical size between the 9x19mm and the Super is easily seen. The two JHP's seen on the left are with Hornady XTP bullets. The two rounds at the right are factory ball.


Physical Descriptions:  Both of these rounds were developed near the turn of the last century with the 9mm hitting the scene in 1902. It was derived from the earlier .30 Luger round.  The .38 Super is dimensionally the same as the lower pressure .38 ACP.


9mm:  This one has a maximum length overall of 1.169" with the case length normally being a maximum length of 0.754." Generally this rimless cartridge measures no more than 0.394 at the rim.  (Rimless simply means that the lip of the rim does not extend wider than the case.) Just above the extractor groove, the case is no more than 0.391" wide and tapers to 0.380" at the case mouth.  The round operates in about the 33,500 to 34,000 PSI range in most loadings.


.38 Super:  This cartridge operates in the same pressure range as the 9mm for the most part and has a non-tapered case measuring about 0.384" wide and 0.9" long at the maximum.  It is a semi-rimmed cartridge and the rim is approximately 0.406" wide.  The cartridge is loaded to a maximum LOA of 1.280." This is very close to the .45 ACP maximum LOA of 1.275."


Both of these cartridges have suffered from unique problems in the past.  The 9mm's dimensions were known to vary wildly as the round has been produced about everywhere on earth and for years no particular emphasis was placed on the ammunition being particularly accurate.  Likewise, the .38 Super had a reputation for dismal accuracy, although this turned out to be caused by early versions of the guns firing it trying to headspace the round off the semi-rim.  In later years, 9mm ammunition has become much more accurate in my experience.  I believe that in the '80's when the US police began flocking to it, the ammo makers truly improved not only bullet performance, but also consistency and accuracy in their products as considerable testing took place.  To win, they had to have accurate, reliable ammo.  Likewise, when pistol makers began building their guns to headspace the .38 Super off the case mouth, vast improvements were seen in the round's accuracy potential.


Power:  Looking at the 9mm next to the .38 Super, it appears that the latter would be the more powerful.  After all, they both operate in the same pressure range and there's simply more case capacity with the .38 Super.  It turns out that while the potential is certainly there, factory rounds with notable exception do not provide more potent loads than do 9mm +P loads.  Let's take a look at some actual chronograph results for both the .38 Super and the 9mm.  The velocities cited are based on 10-shot averages fired approximately 10' from the chronograph screens. When possible, I'll use the 5" barrel Taurus PT-92 figures, as the test gun for the .38 Super is an STI Trojan with a 5" barrel.  Unfortunately, I don't have as much data for this gun as for the slightly shorter barrel (4 22/32") Hi Power, but will note when those figures are used.


9mm Velocities:


Speer 124-gr TMJ: 1182 ft/sec


Corbon 100-gr PowRball +P: 1476 ft/sec


Triton 125-gr Hi Vel JHP +P: 1301 ft/sec


Corbon 115-gr JHP +P: 1411 ft/sec (Browning Mk III Hi Power)


.38 Super Velocities:


PMC 130-gr FMJ +P: 1091 ft/sec


Remington UMC 130-gr FMJ +P: 1231 ft/sec


Corbon 100-gr PowRball +P: 1583 ft/sec


Corbon 115-gr JHP +P: 1467 ft/sec


Corbon 125-gr JHP +P: 1448 ft/sec


Let's look at the Speer 124 grain TMJ vs. the two 130 grain .38 Super FMJ loads.  It is true that the Super bullet is heavier, but I see them as equivalent as 6 grains is actually but 6/7000ths of a pound.  As these bullets do not expand, I'll venture that there is no difference on the receiving end from the 9mm Speer @ 1182 ft/sec and the .38 Super PMC ball load at 91 ft/sec less velocity. Remington's 130-gr FMJ was the fastest of the lot, but still left the barrel at but 49 ft/sec faster than the 9mm Speer TMJ.  In my mind there's enough velocity standard deviation to obliterate the ballistic lines between any of these non-expanding slugs.


Using 115-gr JHP's, we find that the .38 Super bests the 9mm load from the same maker by 56 ft/sec, but 100-gr PowRball in .38 Super shows a more significant velocity gain of 107 ft/sec. With the 125 grain JHP ammunition, the .38 Super also shows a gain of 147 ft/sec. I think that we would see more significant changes in the heavier 147grain bullets in the Super as it has more case capacity, but none of the "big three" ammunition makers offer such.  We begin to see it with the 125-grain loads, but in the 115-grain load range, I see the two as ballistically equivalent. There are some smaller ammo makers who do offer the .38 Super in the heavier bullet weight.


Corbon, while not unknown by any means, is not as widely distributed as are Winchester, Federal, or Remington.  Right now, one can get Winchester's 125 grain Silvertip in .38 Super. While I have not chronographed this load from my STI, it is advertised at 1250 ft/sec.  In other words, it's equivalent to the 9mm +P loads in the same bullet weight. I find it odd that some writers who disparage the 9mm as a defensive round, recommend this .38 Super load as being "potent."  It appears to me that they're the same. If one is "good," so is the other and visa-versa.


It appears that the truth is .38 Super can be found in a few loads where it is more powerful than 9mm, or at least faster. At this point, an advantage that the Super has over the 9mm is missed: While the 9mm can match the .38 Super in some loads, these are maximum effort, maximum pressure loads.  Probably out of concerns over older .38 ACP pistols, I do not believe that the Super is loaded to the same levels of performance other than by Corbon and perhaps some smaller makers.  Were this done, I do believe that the Super would consistently come out on top in this ballistic comparison. In factory trim, the .38 Super has much potential that's not yet been exploited. The 9mm is probably about as "hot" as it can be unless some new, "super powder" is discovered.


Observations: Prospective buyers have considerably less choice in pistols chambered for .38 Super compared to 9mm.  Either caliber can be had in some makes of 1911 pistols and the Super is available in the SIG-Sauer P-220 as well as some of the Tanfoglio Witness-line pistols. 9mm is all over the map with pistols from 6" 1911's to small handguns like the Glock 26. (FWIW, the Glock 26 with its short barrel gets almost the same velocities as the service size 9mm's with some loads, a testament to the research done on the 9mm that the Super has not been afforded.)


The physical size of the Super limits its being offered in truly compact handguns compared to the significantly smaller 9mm.  Another factor to consider is that 9mm and 9x18mm Makarov are probably the least expensive centerfire handgun rounds to be found.  Even in its generic form the Remington UMC ball loads cost around $15 for fifty, compared to the normal $5 to $7 per box of 9mm FMJ.


At this time, I see the 9mm as not giving up enough to be significant for the fellow wanting to buy a pistol for protection and he'll certainly have more selection.  Additionally, he or she will more likely be able to afford ammo for practice than if using the Super. I emphatically am not suggesting that one avoid the .38 Super if that's desired, but that choices will be more limited, ballistic gains not that much for the most part, and ammunition will be considerably higher.


To me, the Super shines as a handloader's cartridge. The STI Trojan I use has the same bore diameter as the company's pistols in 9mm so I get a plethora of bullets from which to choose. Loading data is plentiful for the heavier bullets as well as those from 90 to 130 grains. Cases can be reused and 9mm bullet styles are plentiful. In addition, for folks having problems with feeding due to the round's semi-rim, Starline Brass offers what they call ".38 Super Comp" cases.  These are .38 Super cases without the semi-rim, i.e., a rimless version of the Super.  Occasionally, extractors have to be tweaked, but frequently they work fine as is.  I will be experimenting with this in the near future.


Some use the Super in competitions of various types and load it much hotter than is recommended by any of the loading manuals.  I don't do this, but remain in the ballistic envelope provided by these folks. Right now, I have two loads for the Super that I do think offer significant potential over the 9mm for field use.


One uses Hornady's 147-gr XTP over 8.6 grains of Blue Dot while the other is with Remington's Golden Saber in the same weight.  It's loaded over 8.4 grains of Blue Dot. Velocities from the Trojan are 1229 ft/sec and 1182 ft/sec, respectively.  The fastest I've seen 147-gr bullets fired from a Browning Hi Power is 1033 ft/sec so we're getting 149 ft/sec gains with one and 196 ft/sec with the other. Using the heavier bullet, the velocity should hold better at distances of 50 yards or so than the 9mm with lighter bullet weights and offer more penetration, something that's most desirable in a hunting situation.


These are the two .38 Super handloads mentioned.  The expanded bullets were fired into water and wetpack with surprisingly consistent results.


On the left, we see 3 9mm expanded bullets compared to expanded .38 Supers on the right. At the top left, I substituted an unloaded Hornady 124-gr XTP as I didn't have any of their factory CQ ammunition at hand to show with the expanded 124-gr below it. The far left bullet and cartridge are Winchester's 127-gr +P+ RA9TA while the bottom is PMC Starfire, a standard pressure 124-gr JHP.  The expanded bullet on the far right is Corbon's 125-gr JHP +P compared to the two handloads discussed previously.


Corbon 100-gr PowRball is available for the .38 Super and is faster than the same bullet fired from the 9mm.



Here you can see the expansion results from Corbon's offerings in .38 Super.  The column on the left are expanded 115-gr JHP+P.  The middle column is their 125-gr JHP +P while the last row is their 100-gr PowRball.  All of these were fired into wetpack.


Fired from a CZ-75, this 9mm 100-gr PowRball expanded in similar fashion to the .38 Super.  This one was fired into water.


It's my observation that while the .38 Super has the potential to be significantly more potent than the 9mm, for the most part such is not the case yet.  Unless a handloader, I personally don't see current differences being worth the downside in weapon choice and ammo costs between it and the 9mm.  This is not to say that I don't like the Super as just the opposite it true.  If the ammo companies would take this round to the same development levels that they have with both 9mm and .45 ACP, I think it would truly be a step ahead of 9mm.