This has been brought up over the years that today's +P .38 Spl. ammo is at the same velocity that older ammo has always been loaded at. Based on what GROK AI has to say on the subject, it sounds like this is true.
Yes, there is substantial evidence from historical catalogs, reloading manuals, and ballistics discussions that .38 Special ammunition from the 1920s to the 1960s was often loaded to higher pressures—equivalent to or exceeding modern .38 Special +P levels (20,000 PSI per current SAAMI standards)—resulting in higher velocities than today's standard-pressure .38 Special loads (limited to 17,000 PSI). This shift occurred around the early 1970s when SAAMI formalized lower pressure standards for standard .38 Special to improve safety in lighter revolvers and reduce liability, while designating +P for hotter loads. Pre-1972 loads weren't always explicitly rated in PSI (often measured in Copper Units of Pressure, or CUP, with equivalents around 18,500–20,000 CUP for what became +P), but velocity data serves as a proxy for pressure, as higher velocities indicate higher pressures in comparable test setups.
Below, I'll summarize the key historical context and provide direct velocity comparisons based on reliable sources, including old catalogs, chronographed tests of vintage ammo, and modern benchmarks. Velocities are typically reported from 4-inch or 6-inch barrels (common for testing), as barrel length affects results by ~50–100 fps per inch. Bullet weights focus on the common 158-grain lead round nose (LRN) or similar, as it's the standard for comparisons.
Historical Context
• 1920s–1930s: .38 Special was developed in 1898 as a higher-velocity upgrade over the .38 Long Colt, with early loads pushing 100–150 fps faster. By the late 1920s, law enforcement demands led to "high-speed" variants like the .38 Super Police (200-grain bullet) and .38/44 Hi-Speed (158-grain at ~1,100 fps from a 5-inch barrel, ~20,000 PSI). These were not +P by name but operated at pressures now considered +P.
• 1940s–1960s: Military and police loads varied. WWII-era loads (e.g., 158-grain FMJ) hit 850 fps from 4-inch barrels. Post-war, standard commercial loads remained hot, with U.S. Air Force M41 (130-grain FMJ, 16,000 PSI) at 750 fps from 4-inch and 950 fps from 6-inch. Experimental +P-like loads in the 1950s–1960s reached 18,500 CUP (~20,000 PSI today). Vintage ammo tests show velocities aligning with modern +P.
• 1970s Shift: In 1972, SAAMI standardized standard .38 Special at lower pressures (now 17,000 PSI) to accommodate alloy-frame revolvers, while +P (20,000 PSI) preserved the hotter pre-1972 performance. The FBI Load (158-grain LSWCHP +P) was introduced in 1972 as a response to underperformance of the milder standard loads. Pre-1972 "standard" ammo was often equivalent to modern +P, with no formal distinction.
Velocity Comparisons: Historical vs. Modern
Velocities are approximate averages; actual results vary by barrel length, ammo brand, and testing conditions. Modern data is from SAAMI reference specs (vented test barrels simulate revolvers) and manufacturer catalogs (e.g., Federal, Remington). Historical data comes from catalogs, reloading manuals, and chronographed vintage ammo.
158-Grain Bullet (Most Common for Comparisons)
• Historical (1920s–1960s):
• 1940 Catalog (standard load): 960 fps (test barrel not specified, likely 6-inch or vented).
• 1950s Peters LRN: 800 fps from 4-inch.
• 1950s Remington Hi-Speed: 920 fps from 4-inch.
• Late 1960s Remington LRN: 840 fps from 4-inch.
• Mid-1960s Western Super-X LRN: 810 fps from 4-inch.
• 1958 Lyman Manual (standard load): 825–972 fps (various powders, 4-inch assumed).
• Typical 1940s–1960s police/service: 800–840 fps from 4-inch, 700 fps from 2-inch.
• Modern Standard-Pressure (17,000 PSI):
• SAAMI Reference: 750 fps (test barrel), 900 fps (vented barrel).
• Federal/Remington LRN: 730–800 fps from 4-inch, 700–750 fps from 2-inch.
• Comparison: 50–200 fps slower than 1940s–1960s equivalents, reflecting lower pressure.
• Modern +P (20,000 PSI):
• SAAMI Reference: 880 fps (test barrel), 1,050 fps (vented barrel).
• Federal/Remington LSWCHP or JHP: 850–950 fps from 4-inch, 785–825 fps from 2-inch.
• Comparison: Matches or slightly exceeds pre-1972 velocities (e.g., 920–960 fps historical highs align with modern +P).
Other Bullet Weights (Examples)
• 130-Grain:
• Historical (1960s M41 Military): 750 fps from 4-inch, 950 fps from 6-inch (16,000 PSI).
• Modern Standard: 775–895 fps (test barrel).
• Modern +P: 925 fps (test barrel), 1,150 fps (vented).
• 110-Grain:
• Historical (1930s Hi-Speed): ~1,100–1,390 fps (high-pressure variants).
• Modern Standard: 945–1,000 fps (test barrel).
• Modern +P: 980 fps (test barrel), 1,075–1,205 fps (vented).
Key Takeaways
• Pre-1972 .38 Special was indeed "hotter," often at +P-equivalent pressures, delivering velocities 100–200 fps higher than today's standard loads for the same bullet weight and barrel length. This made it more effective for penetration and stopping power but harder on lighter guns.
• Modern +P restores that performance but is labeled for use only in +P-rated revolvers to avoid damage.
• Sources like vintage catalogs (e.g., 1940 Remington) and manuals (e.g., 1958 Lyman) provide the most direct data, while chronographed tests of surviving ammo confirm the trend. Note that exact pressures pre-1972 weren't always documented in PSI, and CUP-to-PSI conversions aren't linear (e.g., 18,500 CUP ≈ 20,000 PSI for .38 Special). If you have a specific load or barrel length in mind, I can refine the comparison!
Yes, there is substantial evidence from historical catalogs, reloading manuals, and ballistics discussions that .38 Special ammunition from the 1920s to the 1960s was often loaded to higher pressures—equivalent to or exceeding modern .38 Special +P levels (20,000 PSI per current SAAMI standards)—resulting in higher velocities than today's standard-pressure .38 Special loads (limited to 17,000 PSI). This shift occurred around the early 1970s when SAAMI formalized lower pressure standards for standard .38 Special to improve safety in lighter revolvers and reduce liability, while designating +P for hotter loads. Pre-1972 loads weren't always explicitly rated in PSI (often measured in Copper Units of Pressure, or CUP, with equivalents around 18,500–20,000 CUP for what became +P), but velocity data serves as a proxy for pressure, as higher velocities indicate higher pressures in comparable test setups.
Below, I'll summarize the key historical context and provide direct velocity comparisons based on reliable sources, including old catalogs, chronographed tests of vintage ammo, and modern benchmarks. Velocities are typically reported from 4-inch or 6-inch barrels (common for testing), as barrel length affects results by ~50–100 fps per inch. Bullet weights focus on the common 158-grain lead round nose (LRN) or similar, as it's the standard for comparisons.
Historical Context
• 1920s–1930s: .38 Special was developed in 1898 as a higher-velocity upgrade over the .38 Long Colt, with early loads pushing 100–150 fps faster. By the late 1920s, law enforcement demands led to "high-speed" variants like the .38 Super Police (200-grain bullet) and .38/44 Hi-Speed (158-grain at ~1,100 fps from a 5-inch barrel, ~20,000 PSI). These were not +P by name but operated at pressures now considered +P.
• 1940s–1960s: Military and police loads varied. WWII-era loads (e.g., 158-grain FMJ) hit 850 fps from 4-inch barrels. Post-war, standard commercial loads remained hot, with U.S. Air Force M41 (130-grain FMJ, 16,000 PSI) at 750 fps from 4-inch and 950 fps from 6-inch. Experimental +P-like loads in the 1950s–1960s reached 18,500 CUP (~20,000 PSI today). Vintage ammo tests show velocities aligning with modern +P.
• 1970s Shift: In 1972, SAAMI standardized standard .38 Special at lower pressures (now 17,000 PSI) to accommodate alloy-frame revolvers, while +P (20,000 PSI) preserved the hotter pre-1972 performance. The FBI Load (158-grain LSWCHP +P) was introduced in 1972 as a response to underperformance of the milder standard loads. Pre-1972 "standard" ammo was often equivalent to modern +P, with no formal distinction.
Velocity Comparisons: Historical vs. Modern
Velocities are approximate averages; actual results vary by barrel length, ammo brand, and testing conditions. Modern data is from SAAMI reference specs (vented test barrels simulate revolvers) and manufacturer catalogs (e.g., Federal, Remington). Historical data comes from catalogs, reloading manuals, and chronographed vintage ammo.
158-Grain Bullet (Most Common for Comparisons)
• Historical (1920s–1960s):
• 1940 Catalog (standard load): 960 fps (test barrel not specified, likely 6-inch or vented).
• 1950s Peters LRN: 800 fps from 4-inch.
• 1950s Remington Hi-Speed: 920 fps from 4-inch.
• Late 1960s Remington LRN: 840 fps from 4-inch.
• Mid-1960s Western Super-X LRN: 810 fps from 4-inch.
• 1958 Lyman Manual (standard load): 825–972 fps (various powders, 4-inch assumed).
• Typical 1940s–1960s police/service: 800–840 fps from 4-inch, 700 fps from 2-inch.
• Modern Standard-Pressure (17,000 PSI):
• SAAMI Reference: 750 fps (test barrel), 900 fps (vented barrel).
• Federal/Remington LRN: 730–800 fps from 4-inch, 700–750 fps from 2-inch.
• Comparison: 50–200 fps slower than 1940s–1960s equivalents, reflecting lower pressure.
• Modern +P (20,000 PSI):
• SAAMI Reference: 880 fps (test barrel), 1,050 fps (vented barrel).
• Federal/Remington LSWCHP or JHP: 850–950 fps from 4-inch, 785–825 fps from 2-inch.
• Comparison: Matches or slightly exceeds pre-1972 velocities (e.g., 920–960 fps historical highs align with modern +P).
Other Bullet Weights (Examples)
• 130-Grain:
• Historical (1960s M41 Military): 750 fps from 4-inch, 950 fps from 6-inch (16,000 PSI).
• Modern Standard: 775–895 fps (test barrel).
• Modern +P: 925 fps (test barrel), 1,150 fps (vented).
• 110-Grain:
• Historical (1930s Hi-Speed): ~1,100–1,390 fps (high-pressure variants).
• Modern Standard: 945–1,000 fps (test barrel).
• Modern +P: 980 fps (test barrel), 1,075–1,205 fps (vented).
Key Takeaways
• Pre-1972 .38 Special was indeed "hotter," often at +P-equivalent pressures, delivering velocities 100–200 fps higher than today's standard loads for the same bullet weight and barrel length. This made it more effective for penetration and stopping power but harder on lighter guns.
• Modern +P restores that performance but is labeled for use only in +P-rated revolvers to avoid damage.
• Sources like vintage catalogs (e.g., 1940 Remington) and manuals (e.g., 1958 Lyman) provide the most direct data, while chronographed tests of surviving ammo confirm the trend. Note that exact pressures pre-1972 weren't always documented in PSI, and CUP-to-PSI conversions aren't linear (e.g., 18,500 CUP ≈ 20,000 PSI for .38 Special). If you have a specific load or barrel length in mind, I can refine the comparison!
