What is .38 Special +P and how it differs from standard pressure
.38 Special +P refers to +P and +P+ loadings of .38 Special ammunition that exceed the standard SAAMI pressure ceiling. Standard .38 Special is pressure-limited at 15,500 psi by SAAMI. +P is loaded to higher pressures within SAAMI’s allowance, and +P+ exceeds those limits further. Because no commercial SAAMI specification exists for +P+, some manufacturers treat it as a +P loading and list pressures typically in the 18,500 psi range. In short, the plus ratings indicate hotter loads designed for modern firearms built to handle them, not improvements in inherent accuracy.
Pressure specifications and SAAMI standards at a glance
Understanding pressure standards helps clarify what +P and +P+ mean in practice and why they are not universally specified across all revolvers and semi-autos chambered for .38 Special. Industry standards and typical manufacturer data provide the following reference points.
| Designation | Typical Maximum Pressure | SAAMI Specification | Notes |
|---|---|---|---|
| .38 Special Standard | 15,500 psi | SAAMI | Baseline pressure for standard loads |
| .38 Special +P | 18,500 psi | SAAMI | Higher pressure, modern firearms only |
| .38 Special +P+ | 20,000 psi | SAAMI | Higher still; verify firearm suitability |
| .38 Special +P+ (unofficial) | ~18,500–20,000 psi | No commercial SAAMI spec | Manufacturer-dependent; consult data |
Interpreting the numbers
Pressure ratings are not ratings of quality or precision; they reflect maximum chamber pressures in pounds per square inch (psi). A +P or +P+ round can deliver more velocity and energy, but only when the firearm is rated and designed for those pressures. Using them in guns not rated for higher pressure increases risk of case rupture or component failure.
Firearms approved for .38 Special +P and +P+
Not every gun labeled .38 Special can safely handle +P or +P+ ammunition. Revolvers and semi-automatic pistols must be explicitly marked for these higher-pressure rounds. Always consult the manufacturer’s specifications and avoid relying solely on caliber markings.
Revolvers commonly rated for +P
- Smith & Wesson models marked "P+" or "+P" (many J-frame and medium-frame revolvers)
- Ruger Blackhawk, Redhawk, and newer SP101 models when so marked
- Colpython, Anaconda, and certain other premium revolvers with appropriate metallurgy
Semi-automatics typically rated for +P
- Glock pistols chambered in .38 Super, which is a different cartridge but demonstrates high-pressure handling; .38 Special +P pistads are less common and must be verified
- Some older .38 Super–labeled pistols may not accept .38 Special +P unless explicitly stated
- Manufacturers such as Smith & Wesson and others sometimes offer .38 Special–chambered autos rated for +P; check documentation
Performance differences: recoil, velocity, and trajectory
Because +P and +P+ operate at higher chamber pressures, they generally produce higher muzzle velocities and flatter trajectories compared to standard-pressure .38 Special. This can translate to slightly more recoil and sharper report, which may affect comfort and speed of follow-up shots. The actual difference in felt recoil depends on firearm weight, grip, and load choice. In defensive scenarios, the performance gains are often modest but can be meaningful in specific applications where velocity is critical.
When to choose .38 Special +P or +P+
Use +P or +P+ only when your firearm is explicitly rated for them. These loads can be attractive for defensive use, competitive shooting, or situations where extra velocity is desired. For routine practice and range training, standard-pressure .38 Special is typically more economical and produces less wear and recoil. When in doubt, consult the gunsmith or manufacturer before feeding these hotter rounds to your firearm.
Reliability, longevity, and maintenance considerations
Higher-pressure rounds can increase stress on locks, extractors, and cylinder gaps in revolvers. Over time, firing +P or +P+ may accelerate wear compared to standard-pressure ammunition. Inspect for signs of pressure signs—such as primer flattening or firing pin indents—and adhere to manufacturer maintenance schedules. If you frequently shoot +P or +P+, consider more frequent servicing of moving parts and cylinders to ensure long-term reliability.