Picture this: My buddy, let’s call him Dave, recently picked up his first revolver, a beautiful classic .38 Special. He was all excited, heading to the range, and grabbed a box of what he thought was just “revolver ammo.” He hadn’t quite grasped the subtle, yet incredibly significant, distinctions between calibers. Standing there, at the firing line, he was about to try and chamber a .357 Magnum round into his .38 Special cylinder. Luckily, I was there, and a quick glance at the ammo box made my heart jump into my throat. “Whoa there, partner!” I exclaimed, stopping him just in time. “You absolutely, positively, cannot shoot .357 from your .38 Special.”
And that, folks, is the immediate and unequivocal answer to the question: No, you cannot shoot .357 Magnum ammunition from a .38 Special firearm. It is extremely dangerous, can lead to catastrophic failure of your firearm, and result in severe injury or even death.
This isn’t just a friendly suggestion; it’s a critical safety rule in the world of firearms. While these two cartridges might look similar to the untrained eye, and even share the same bullet diameter, their differences in case length and, more importantly, chamber pressure, make them entirely incompatible for cross-use in the wrong firearm. Let’s dive deep into why this seemingly small distinction is a monumental one, and explore the serious consequences of ignoring it.
The Critical Difference: .38 Special vs. .357 Magnum
To truly grasp why attempting to fire a .357 Magnum round from a .38 Special revolver is a recipe for disaster, we need to understand the fundamental differences between these two cartridges. While they might seem like kissing cousins, they’re more like siblings with vastly different temperaments and capabilities.
Case Length: A Physical Barrier (Mostly)
The most obvious difference, and one designed specifically as a safety feature, is the case length. The .38 Special cartridge case measures approximately 1.155 inches. The .357 Magnum, on the other hand, is noticeably longer at about 1.290 inches. This difference, roughly an eighth of an inch, is crucial.
- .38 Special Chambers: A .38 Special revolver’s cylinder chambers are designed to precisely fit the shorter .38 Special cartridge.
- .357 Magnum Chambers: A .357 Magnum revolver’s chambers are longer, designed to accommodate the .357 Magnum round.
Now, here’s where the confusion can sometimes creep in for folks new to firearms. A .38 Special round *can* be fired from a .357 Magnum revolver because the shorter .38 Special cartridge fits within the longer .357 Magnum chamber. There’s a bit of extra space, but it’s generally safe because the bullet still engages the forcing cone correctly and the pressures are well within the firearm’s limits. However, the reverse is not true. The longer .357 Magnum round simply won’t fully seat in a .38 Special chamber. It will protrude slightly, preventing the cylinder from closing completely in most revolvers, or, in some older or less precisely manufactured firearms, it might *seem* to close, but the cartridge won’t be fully supported.
Chamber Pressure: The Invisible Killer
While case length is a visible indicator, the real danger lies in the invisible force of chamber pressure. This is where the .357 Magnum truly earns its “Magnum” designation. The amount of gunpowder loaded into a cartridge dictates the pressure generated when it’s ignited. The .357 Magnum is designed to generate significantly higher pressures than the .38 Special.
Let’s look at the industry standards set by SAAMI (Sporting Arms and Ammunition Manufacturers’ Institute), which are vital for firearm and ammunition safety:
- .38 Special SAAMI Max Pressure: Standard .38 Special loads typically operate at a maximum average pressure (MAP) of around 17,000 PSI (pounds per square inch). There are also +P loads for .38 Special, which are slightly hotter, pushing pressures up to about 20,000 PSI. These are still designed to be fired only in .38 Special revolvers rated for +P ammunition.
- .357 Magnum SAAMI Max Pressure: In stark contrast, the .357 Magnum operates at a MAP of around 35,000 PSI.
That’s more than double the pressure of a standard .38 Special and nearly double that of a .38 Special +P! Imagine putting twice the force on a component designed for half that stress. It’s like trying to put a V8 engine in a compact car designed for a four-cylinder. The consequences are, predictably, catastrophic.
Powder Charge and Velocity: Power Demands Strength
The increased pressure in a .357 Magnum round comes from a greater volume of a different, often slower-burning, gunpowder and sometimes a slightly heavier bullet, all designed to achieve much higher muzzle velocities and energy. A .357 Magnum round can achieve velocities upwards of 1,250-1,450 feet per second (fps), while a .38 Special typically ranges from 750-950 fps.
This raw power, this incredible boost in performance, necessitates a much more robust firearm. The components of a .357 Magnum revolver – the cylinder, frame, and barrel – are engineered and constructed from stronger materials and with different tolerances to safely contain these immense forces. A .38 Special revolver simply isn’t built for that kind of stress.
Why a .38 Special Revolver Can’t Handle It
Understanding the pressure difference is key, but let’s break down exactly which parts of your .38 Special revolver are at risk and why they will likely fail under .357 Magnum pressure.
The Cylinder: The Primary Point of Failure
The cylinder is the heart of a revolver, holding the cartridges and containing the initial explosion. When a round is fired, the walls of the cylinder bear the full brunt of the chamber pressure. A .38 Special cylinder is manufactured with specific wall thicknesses and material strengths to withstand 17,000-20,000 PSI safely, repeatedly.
When you try to fire a 35,000 PSI .357 Magnum round in that cylinder, you are subjecting it to nearly double the force it was designed to handle. The material will simply give way. This isn’t a “maybe it’ll be okay” situation; it’s a “when, not if” scenario for failure. The cylinder can:
- Rupture or Explode: The most common and dangerous outcome. The cylinder walls will crack, fragment, and violently explode outwards, sending shrapnel in all directions.
- Crack or Bulge: Even if it doesn’t immediately explode, the cylinder can crack, bulge, or deform, making the firearm permanently unsafe and potentially failing on subsequent shots.
The Frame: The Foundation Under Duress
The frame of a revolver is its backbone, holding all the components together. While the cylinder takes the direct pressure, the frame absorbs the recoil and is stressed by the force of the expanding gases. .38 Special frames are typically made from steel, but often with less robust designs or materials compared to their .357 Magnum counterparts, which might use stronger alloys or heavier construction.
If the cylinder fails, the frame will also be severely compromised. The forces released by a cylinder explosion can:
- Shatter or Deform the Frame: The frame can crack, twist, or break apart, rendering the firearm completely inoperable and potentially sending metal fragments toward the shooter.
- Cause Other Component Failures: Parts like the trigger mechanism, hammer, or cylinder crane can be damaged or dislodged, creating further hazards.
The Barrel: Not Immune to Overpressure
While less common than cylinder failure, the barrel is also at risk. The barrel of a .38 Special revolver is dimensioned for the specific pressures and velocities of the .38 Special cartridge. Firing a .357 Magnum round generates a pressure wave that the barrel may not be able to contain without stretching, bulging, or even bursting, especially near the forcing cone where the bullet transitions from the cylinder into the barrel.
Beyond the structural integrity, even if the gun miraculously didn’t explode, the extreme force would accelerate wear and tear, leading to premature failure, loss of accuracy, and instability.
The Dangers Are Real: Catastrophic Failure & Injury
Let’s not mince words here. Trying to fire a .357 Magnum in a .38 Special is not just “bad for your gun.” It is incredibly, seriously, life-alteringly dangerous. We’re talking about an event that can permanently disable you, or worse. This isn’t theoretical; these incidents happen, and the consequences are devastating.
Exploding Revolvers: A Violent End
When a .38 Special cylinder gives way under .357 Magnum pressures, it’s not a gentle puff. It’s an explosion. The steel components of the cylinder, designed to hold back incredible force, fragment violently. These fragments turn into high-velocity shrapnel, tearing through anything in their path. Imagine a hand grenade going off in your hand, only designed to direct its force primarily outward from the cylinder gap and sides.
Severe Physical Injuries
The primary target of this shrapnel is, unfortunately, the shooter. Your hands, holding the firearm, are in the direct line of fire. Fragments can tear through flesh, bone, and tendon. We’re talking about:
- Hand Trauma: Lacerations, deep punctures, broken bones, severed fingers, or even the loss of a hand.
- Facial Injuries: Pieces of metal can fly backward, causing severe damage to your face, eyes (leading to permanent blindness), and teeth.
- Hearing Loss: The concussive blast is immensely loud, far exceeding safe levels, potentially causing permanent hearing damage or rupture of eardrums.
- Soft Tissue Damage: Fragments can embed themselves anywhere, requiring complex surgery and leading to lasting pain and disfigurement.
These aren’t minor scrapes; they are injuries that can fundamentally alter your life, requiring extensive medical treatment, rehabilitation, and potentially multiple surgeries. The emotional and psychological toll can be just as significant.
Permanent Firearm Damage: Beyond Repair
Beyond the physical danger to yourself, your firearm will almost certainly be destroyed. A revolver that has suffered a catastrophic failure due to overpressure is, in nearly all cases, irreparable. The frame will be compromised, the cylinder shattered, and the barrel likely damaged. It becomes a twisted, dangerous piece of scrap metal, fit only for the junk heap. No gunsmith in their right mind would attempt to repair a firearm that has experienced such a failure; its structural integrity is permanently compromised, making it a liability and a danger even if it *looked* like it could be fixed.
Legal and Ethical Ramifications
If you intentionally attempt to fire incompatible ammunition, any warranty on your firearm is immediately voided. More significantly, if someone else were to get injured due to your negligence (e.g., if you loaded the wrong ammo into a shared range gun), you could face severe legal consequences. Responsible firearm ownership demands careful attention to safety and ammunition compatibility. Ignorance is not a valid defense when it comes to risking lives.
The One-Way Street: .38 Special in a .357 Magnum Revolver (The Safe Exception)
Now, to clear up a common point of confusion, let’s talk about the *only* acceptable and safe cross-compatibility between these two calibers. While you can never put a .357 Magnum into a .38 Special, you absolutely *can* shoot .38 Special ammunition from a revolver chambered for .357 Magnum.
Why is this safe? It all comes back to the engineering and design principles we discussed:
- Longer Chambers: A .357 Magnum chamber is longer and wider at the mouth to accommodate the larger .357 Magnum case. The shorter .38 Special case fits comfortably within this chamber.
- Overbuilt Strength: A .357 Magnum revolver is built to withstand pressures of 35,000 PSI. The 17,000-20,000 PSI generated by a .38 Special round is well within its safety margins. The firearm is significantly “over-engineered” for the .38 Special round, making it perfectly safe.
Many shooters who own .357 Magnum revolvers regularly use .38 Special ammunition for practice, target shooting, or simply to enjoy a milder recoil experience. It’s often more economical for range use and provides less wear and tear on the firearm, as well as being more comfortable for extended shooting sessions.
There’s one minor consideration when consistently shooting .38 Special in a .357 Magnum: lead fouling. The shorter .38 Special case leaves a small ring of carbon and lead residue in the front portion of the longer .357 Magnum chamber. If this residue builds up significantly, it can make it difficult or impossible to chamber a full-length .357 Magnum round later on. A thorough cleaning of the chambers after shooting .38 Special is always a good practice to prevent this buildup and ensure reliable chambering of .357 Magnum rounds when you switch back.
Identifying Your Firearm and Ammunition: A Vital Checklist
Preventing a catastrophic incident starts with diligent attention to detail. Every responsible firearm owner should make it a habit to double-check their gear and ammunition. Here’s a quick checklist to ensure you’re always using the right ammo in the right gun:
Always Verify Your Firearm’s Caliber
- Check the Barrel Marking: This is the most critical place to look. The caliber of your firearm is almost always stamped clearly on the barrel. For revolvers, it might be on the side of the barrel or on the frame near the cylinder. Look for “38 SPL,” “.38 S&W Special,” “.357 Magnum,” or simply “.357 MAG.” If it says “.38 Special,” that’s what it is. If it says “.357 Magnum,” it can handle both .357 Magnum and .38 Special.
- Consult the Owner’s Manual: If you’re unsure or can’t find the marking, refer to the firearm’s owner’s manual. It will explicitly state the correct ammunition.
- When in Doubt, Ask a Professional: If there’s any ambiguity, take your firearm to a reputable gunsmith or experienced firearms dealer. They can identify the exact caliber for you. Never guess!
Always Verify Your Ammunition’s Caliber
- Read the Box: This might seem obvious, but it’s where many mistakes happen. Ammunition boxes are clearly labeled with the caliber. Double-check that it matches your firearm’s designation exactly. Don’t just glance; read it thoroughly.
- Visual Inspection of Cartridges: While less reliable for subtle differences, you can visually compare a known .38 Special round to a .357 Magnum round to see the case length difference. The .357 Magnum will be noticeably longer. This is a good secondary check, but the box is king.
- Never Mix Ammunition: Keep your different calibers separated. If you own both a .38 Special and a .357 Magnum, store their respective ammunition in distinctly labeled containers to prevent accidental mix-ups. This is especially true if you load rounds from loose boxes or containers.
What If I Already Did It (or witnessed it)?
Perhaps you’ve stumbled upon this article after an unfortunate incident, or you witnessed someone else make this critical mistake. What do you do in that scenario?
Immediate Safety Protocols
- Stop Immediately: If the firearm is still in your hand and has *not* fired, carefully unload it. Remove the incompatible round and set it aside. Do not attempt to force the cylinder closed or try to fire it.
- If it Fired: If the firearm discharged and something felt “wrong” – an unusually loud report, excessive recoil, or if you immediately notice damage – stop shooting immediately. Point the firearm in a safe direction.
- Inspect for Damage (from a distance): Do not attempt to cycle the action or fire another round. Carefully visually inspect the firearm, particularly the cylinder, frame, and barrel, for any signs of cracking, bulging, deformation, or missing pieces. Do not touch or manipulate any damaged parts.
- Render Safe: Unload the firearm only if it can be done safely without further damaging the gun or endangering yourself. If it’s severely damaged, leave it pointed in a safe direction and avoid touching it until professional help arrives or you can secure it.
Professional Inspection is Paramount
Regardless of whether the firearm simply failed to close, or actually fired and showed signs of damage, it needs a professional assessment. Do NOT attempt to fire the firearm again, even if it appears superficially undamaged after the incident. The internal stresses could be compromised, leading to a delayed failure.
- Contact a Qualified Gunsmith: Take the firearm to a reputable gunsmith who specializes in revolvers. Explain exactly what happened. They will have the tools and expertise to thoroughly inspect the firearm for structural integrity, hidden cracks, or metallurgical fatigue that might not be visible to the naked eye.
- Expect the Worst: Be prepared for the gunsmith to tell you the firearm is unsafe and irreparable. It’s far better to write off a damaged firearm than to risk life and limb attempting to use a compromised one.
Understanding SAAMI Specifications: The Unseen Guardrails
When we talk about pressure differences, it’s not just arbitrary numbers; it’s about industry standards designed to keep us safe. SAAMI, the Sporting Arms and Ammunition Manufacturers’ Institute, is a cornerstone of firearm safety in the United States. They establish the voluntary technical standards for ammunition and firearms, which include things like cartridge and chamber dimensions, as well as maximum allowable pressures.
These standards are developed by experts and are crucial for ensuring that when you buy a firearm and ammunition of a specified caliber, they will function safely together, provided they are used correctly. The pressure ratings we mentioned earlier – 17,000 PSI for .38 Special and 35,000 PSI for .357 Magnum – are SAAMI Maximum Average Pressures (MAP). These figures are not just theoretical; they are the result of extensive testing and engineering to determine the safe limits for components of a given design and material.
When a firearm manufacturer designs a .38 Special revolver, they adhere to SAAMI specifications for the .38 Special cartridge. This means designing the cylinder, frame, and barrel to safely contain pressures up to and slightly beyond that 17,000 PSI (or 20,000 PSI for +P rated models) limit. They build in a safety margin, but that margin is specifically for the .38 Special’s pressure range, not for literally double that amount.
Similarly, a .357 Magnum revolver is designed to the much higher SAAMI specifications for the .357 Magnum cartridge. This is why their construction is inherently more robust. Adhering to these standards is what allows you to confidently use factory ammunition in your firearm, knowing that extensive research and testing have gone into making that combination safe.
Safe Shooting Practices: A Lifesaving Checklist
Good habits are the best defense against accidents. Incorporate these practices into your firearm routine every single time:
- Always Verify Caliber: Before loading any ammunition into any firearm, pause and double-check both the firearm’s marking and the ammunition box. Make it a non-negotiable step.
- Read Your Manuals: Always read the owner’s manual for your firearm. It contains critical information specific to your model, including approved ammunition types.
- Eye and Ear Protection: This should be a given for any shooting activity, but it becomes even more critical if an unforeseen event, like an overpressure failure, were to occur. Good quality safety glasses and hearing protection can mitigate some of the injury risk.
- Never Force Anything: If a cartridge doesn’t easily chamber or a cylinder doesn’t close smoothly, STOP. Do not apply force. There’s a reason for the resistance, and it’s usually an incompatibility or a mechanical issue that needs addressing.
- Segregate Ammunition: If you own multiple firearms with similar-looking but different calibers (e.g., .38 Special and .357 Magnum, or 9mm and .380 ACP), store their ammunition separately and label containers clearly.
- Be Mindful of Reloads: If you’re a handloader, the responsibility for safety is even greater. Meticulously follow reloading manuals for the specific caliber and bullet/powder combination. Never attempt to “hot rod” loads beyond published data, and never substitute components without consulting reliable data.
- Stay Educated: Continue to learn about firearm safety, ballistics, and proper handling. The more you know, the safer you’ll be.
Reloading Considerations: Precision and Peril
For those who handload their own ammunition, the distinction between .38 Special and .357 Magnum takes on an even greater importance, coupled with significant risks if not approached with utmost care. While you can indeed use the same diameter bullets (typically .357-.358 inch) for both calibers, *everything else* about the reloading process must be specific to the cartridge being assembled.
- Dedicated Dies: You will need separate dies for .38 Special and .357 Magnum. While some die sets might be labeled for both, they often come with a spacer or require adjustments that account for the different case lengths. Using the wrong setting can lead to issues like incorrect bullet seating depth or crimp, both of which can be dangerous.
- Specific Powders and Charges: This is the most critical aspect. The powders and powder charges safe for .38 Special are drastically different from those for .357 Magnum. You absolutely cannot use .357 Magnum powder charges in a .38 Special case, nor should you use .38 Special charges to attempt to load a .357 Magnum round (which would result in squibs or very anemic performance). Always consult multiple, up-to-date reloading manuals and stick to the published data for the specific cartridge, powder, and bullet weight you are using.
- Case Length is King: Ensure your brass is sorted by caliber. Never accidentally load .357 Magnum data into a .38 Special case, or vice-versa. The shorter .38 Special case has less internal volume, meaning a .357 Magnum powder charge in it would generate astronomically dangerous pressures, even in a .357 Magnum firearm.
- Primer Selection: While often interchangeable between standard revolver calibers, some high-pressure loads for .357 Magnum might benefit from a magnum-rated primer, though standard primers are often acceptable. Always follow your reloading manual’s recommendations.
Reloading demands meticulous attention to detail and zero shortcuts. The margin for error is far smaller than with factory ammunition, and the consequences of a mistake can be just as severe.
Why the Confusion Exists
Given the stark dangers, one might wonder why this confusion between .38 Special and .357 Magnum persists. There are a few contributing factors:
- Similar Nomenclature: Both cartridges start with “.38,” leading many new shooters to assume a direct compatibility, much like different brands of gasoline in a car. The addition of “Special” versus “Magnum” can be overlooked or misunderstood.
- Shared Bullet Diameter: Both cartridges use a bullet that nominally measures 0.357-0.358 inches in diameter. This technical similarity can further mislead individuals into believing the cartridges are interchangeable. The “.38” in .38 Special is a historical anachronism referring to the approximate diameter of the *outside* of the case at the rim, not the actual bullet diameter.
- The One-Way Compatibility: Because you *can* shoot .38 Special in a .357 Magnum, some people mistakenly believe the reverse must also be true, failing to understand the critical role of pressure ratings and chamber dimensions.
- Lack of Education: Many new firearm owners don’t receive comprehensive training on ammunition types and compatibility. A quick trip to the gun store and simply asking for “revolver ammo” can lead to dangerous assumptions.
- Historical Evolution: The .357 Magnum was developed from the .38 Special case, essentially an elongated and strengthened version designed to handle higher pressures. This historical lineage, while interesting, can contribute to confusion for those unaware of the specific design changes.
It’s incumbent upon experienced shooters, instructors, and retailers to help educate newcomers on these vital distinctions. Lives and limbs literally depend on it.
My Take: Responsibility, Education, and Safety First
Having spent my fair share of time around firearms and observing countless interactions at the range, I can tell you that the question “Can I shoot .357 from my .38 Special?” is one of the most common and concerning queries I hear. My immediate reaction is always a firm “No!” followed by a detailed explanation, because the stakes are simply too high to leave any room for misunderstanding.
Firearm ownership is a privilege that comes with immense responsibility. Part of that responsibility is a commitment to continuous learning and unwavering adherence to safety protocols. It’s not about being a gun ‘expert’ overnight, but about cultivating a mindset where curiosity about safety trumps assumption, and caution is always prioritized over convenience.
I genuinely believe that most people who consider or accidentally attempt this do so out of a lack of knowledge, not malicious intent. That’s why articles like this, and open conversations within the shooting community, are so crucial. We all have a role to play in ensuring that everyone who handles a firearm does so safely and competently. Double-checking your caliber, understanding the physics behind your ammunition, and never taking shortcuts are not just rules; they are commitments to your own safety and the safety of everyone around you. Let’s make sure we all go home safe at the end of the day, with all our fingers and eyes intact.
Frequently Asked Questions About .38 Special and .357 Magnum Compatibility
Can I use .357 *bullets* when reloading .38 Special cases?
Yes, you absolutely can use .357 diameter bullets when reloading .38 Special cases. Both the .38 Special and .357 Magnum cartridges are designed to use bullets with a nominal diameter of 0.357 inches, or sometimes slightly larger at 0.358 inches for lead bullets.
The key distinction when reloading is not the bullet itself, but the *case* and the *powder charge*. When reloading .38 Special, you must use .38 Special cases and strictly adhere to reloading data specifically published for .38 Special. Never use powder charges meant for .357 Magnum in a .38 Special case, regardless of the bullet used, as this would lead to dangerously high pressures.
What’s the absolute worst that could happen if I try to fire a .357 Magnum in a .38 Special?
The absolute worst outcome is a catastrophic firearm failure, resulting in severe injury or even death. When the .357 Magnum round, with its immense pressure, is fired in a .38 Special revolver not designed to contain it, the cylinder will almost certainly rupture or explode. This violent event will send fragments of the cylinder, frame, and potentially other gun components flying outwards at high velocity.
These metal fragments can cause devastating damage to your hands, leading to broken bones, severed fingers, or permanent disfigurement. They can also fly towards your face and eyes, causing blindness or severe facial trauma. The concussive blast can lead to permanent hearing loss. Beyond personal injury, the firearm itself will be destroyed, becoming a dangerous and irreparable piece of scrap metal. It is not an exaggeration to say that this mistake can be life-altering.
Are all .38 Special revolvers the same, or are some stronger than others?
While there are variations in the strength and construction of .38 Special revolvers, the fundamental rule of not firing .357 Magnum ammunition in them remains universal. Older .38 Special revolvers, particularly those from the early 20th century or made with less robust materials (sometimes referred to as “I-frames” or “J-frames” from certain manufacturers), are often less strong than modern counterparts. Even within modern manufacturing, there can be differences in frame size (e.g., small J-frame vs. larger K-frame revolvers that are only chambered for .38 Special).
Some newer .38 Special revolvers, especially those rated for +P ammunition, are built to withstand slightly higher pressures (up to 20,000 PSI). However, even these stronger .38 Special +P revolvers are still only designed for the .38 Special pressure range, not the 35,000 PSI of a .357 Magnum. The safety margin, while potentially larger than an old gun, is nowhere near sufficient to bridge that gap. Always adhere to the caliber marking on your specific firearm.
Why would someone even try to mix these two calibers in the first place?
Most attempts to mix .357 Magnum and .38 Special ammunition are not intentional acts of recklessness, but rather stem from a combination of ignorance and the visual similarities between the cartridges. New shooters, or those without extensive firearm knowledge, might not understand the subtle but critical differences in case length and pressure.
The fact that both calibers often start with “38” (in the case of .38 Special) and use the same bullet diameter (approximately .357-.358 inch) can be very misleading. Furthermore, the safe practice of shooting .38 Special in a .357 Magnum revolver can lead to a dangerous assumption that the reverse is also permissible. Sometimes, it’s simply an accidental mix-up at the range or when loading from loose ammunition, where a .357 Magnum round mistakenly gets into a box of .38 Special, and a shooter doesn’t double-check the headstamp or case length before loading.
What are “.38 Special +P” loads, and can I shoot them in my standard .38 Special revolver?
.38 Special +P (pronounced “Plus P”) loads are a specific type of .38 Special ammunition that generates higher pressures and velocities than standard .38 Special loads. While standard .38 Special operates at a SAAMI Maximum Average Pressure (MAP) of 17,000 PSI, .38 Special +P loads are rated for a MAP of 20,000 PSI. This provides a modest increase in performance, often desired for self-defense applications.
Whether you can shoot .38 Special +P in your revolver depends on the firearm’s manufacturer. Many modern .38 Special revolvers are explicitly rated for +P ammunition, and this will usually be indicated in the owner’s manual or sometimes stamped on the firearm itself. However, older or lighter-framed .38 Special revolvers may not be rated for +P. Firing +P in a non-+P rated revolver can accelerate wear and tear, and potentially lead to premature failure or reduced service life, though it typically won’t result in the immediate catastrophic failure seen with .357 Magnum in a .38 Special. Always check your firearm’s manual or consult the manufacturer if you are unsure if your .38 Special revolver is rated for +P ammunition. Even with +P loads, you are still well below the pressure levels of a .357 Magnum.
How can I tell if a used gun I’m considering buying has ever been subjected to such an overpressure incident?
Detecting a past overpressure incident in a used firearm can be challenging, as some damage might not be immediately obvious. However, there are signs a knowledgeable eye or gunsmith might spot. First, visually inspect the cylinder carefully for any signs of bulging, cracks (even hairline ones), or uneven gaps where the cylinder meets the frame. Look for any discoloration or stress marks on the steel, especially around the chamber walls.
Next, inspect the frame, particularly around the topstrap (the part above the cylinder) and the area where the barrel meets the frame, for cracks, stretching, or deformation. Check the barrel itself for any bulges. If the cylinder doesn’t align perfectly with the forcing cone, or if there’s excessive play in the cylinder’s rotation or lock-up, these could be indicators of stress. A firearm that has experienced significant overpressure might also have a loose-feeling action or a frame that seems slightly “sprung” or out of true. The most reliable method is to have a qualified gunsmith perform a thorough inspection, including gauge checks and possibly magnafluxing (a method for detecting surface and subsurface flaws), before purchasing any used firearm, especially if there are any doubts about its history.
