Reference / Paper · 2022
SAAMI's American National Standard for centerfire pistol and revolver ammunition: pressure and velocity tables, test methods and cartridge and chamber drawings (approved 13 December 2022). Cited for cartridge pressures and dimensions by the HK Mk23, Ruby Pistol and HK MP7 dives.
American National Standard SAAMI Z299.3-2022 Voluntary Industry Performance Standards for Pressure and Velocity of Centerfire Pistol and Revolver Ammunition for the Use of Commercial Manufacturers Sporting Arms and Ammunition Manufacturers’ Institute, Inc. www.saami.org SAAMI Z299.3 – 2022 Voluntary Industry Performance Standards for Pressure and Velocity of Centerfire Pistol and Revolver Ammunition for the Use of Commercial Manufacturers Sponsor Sporting Arms and Ammunition Manufacturers’ Institute, Inc. Voting Members Beretta USA Corporation Browning Arms Company Federal Cartridge Company Fiocchi of America, Inc. Glock, Inc. Hodgdon Powder Company, Inc. Hornady Manufacturing Kahr Arms New River Energetics North American Arms, Inc. O.F. Mossberg & Sons, Inc. Olin Corporation/Winchester Division Savage Arms, Inc. SIG SAUER Smith & Wesson Corp. St. Marks Powder, Inc. Sturm, Ruger & Co., Inc. Taurus Holdings, Inc. True Velocity Ammunition, LLC Weatherby, Inc. Associate Members: Nosler, Inc Quantum Ammunition, LLC RUAG Ammotech USA, Inc. Supporting & Affiliate Members: Ammo Inc. Armscor Cartridge Inc. Atlas Development Group LLC Barnes Bullets, LLC Black Hills Ammunition, Inc. Blackpowder Products, Inc. (d/b/a Bergara USA) CZ-US Holdings, Inc. DoubleTap Ammunition, Inc. Henry Repeating Arms H-S Precision, Inc. Kent Cartridge, America Kimber Manufacturing Inc Approved December 13, 2022 L-Tech Enterprises, Inc. Modern Muzzleloading (d/b/a Knight Rifles) On Target Ammunition, LLC Prospector Training LLC RWC Group, LLC (d/b/a Kalashnikov USA) Sierra Bullets LLC Southern Ballistic Research, LLC (d/b/a SBR) Specialty Cartridge Inc. (d/b/a Atlanta Arms) Tippmann Arms Co. LLC Traditions Performance Firearms Vairog USA Wilson Combat Abstract In the interests of safety and interchangeability, this Standard provides pressure and velocity performance and dimensional characteristics for centerfire pistol and revolver sporting ammunition and their respective chambers. Included are procedures and equipment for determining these criteria. American National Standard Approval of an American National Standard requires verification by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. The use of American National Standards is completely voluntary; their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standards. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Institute. Requests for interpretation should be addressed to Sporting Arms and Ammunition Manufacturers’ Institute, Inc. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of approval. Purchasers of American National Standards may receive current information of all standards by calling or writing the American National Standards Institute. Published by Sporting Arms and Ammunition Manufacturers’ Institute, Inc. www.saami.org Copyright © 2022 by Sporting Arms and Ammunition Manufacturers’ Institute, Inc. All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. Printed in the United States of America Note: This foreword is not part of SAAMI Z299.3-2022 Foreword The development of this voluntary industry performance standard was initiated under the auspices of the Sporting Arms and Ammunition Manufacturers’ Institute, Inc. (SAAMI). A Products Standards Task Force was established by the Institute in 1975 and charged with the drafting of this and other standards with their subsequent periodic revisions. The material presented provides the commercial manufacturer of factory-loaded ammunition with pressure and velocity performance and dimensional characteristics. Included are procedures and equipment for determining these criteria. For the purpose of this standard a commercial manufacturer is defined as one who produces ammunition by fabricating component parts from raw materials as opposed to remanufacture with parts originally made by others. This standard for Centerfire Pistol and Revolver Sporting Ammunition was first published in 1979 and periodically updated until this revision in 2022. Changes in the standard with each revision include minor adjustments of velocities, the addition of new load offerings, and updating of recommended equipment sources and the latest procedures for reporting reference ammunition assessments. Suggestions for improvement of this standard are welcome and should be sent to: [email protected]. SAAMI’s criteria for obtaining consensus on all proposed standards is a majority of the consensus body casting a vote (counting abstentions) and at least two-thirds (2/3) of those voting approve (not counting abstentions). The consensus body for this standard consisted of the following individuals and their respective affiliations: Interest Category Expert Expert Expert General Interest General Interest General Interest Government Government Producer Producer Producer Testing Laboratory Name Buford Boone Carl Hildebrandt Samuel Perry James E. Hamby Ken Kees Paul Szabo Earl Griffith Mark Greene Bob Metz Oldemar Fonseca Jr Raymond Gross Lowell Johnson Testing Laboratory Testing Laboratory User User User Richard Bowes Richard Poaps A. Scott Patterson Cody Walton Jennifer Floyd Affiliation Boone Ballistics Massachusetts Institute of Firearms Technology Birmingham Proof House Association of Firearms & Tool Mark Examiners Individual, Retired Ammunition Engineer and Avid User Individual, Retired Ammunition Engineer, Expert Witness The Bureau of Alcohol, Tobacco, Firearms and Explosives National Institute of Justice PCB Piezotronics, Inc. Companhia Brasileira de Cartuchos (CBC) Manson Precision Department of Homeland Security (DHS) - National Armory Natural Resources Canada Royal Canadian Mounted Police Federal Bureau of Investigation (FBI) Naval Surface Warfare Center, Crane Division Arkansas State Crime Lab TABLE OF CONTENTS CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS TABLE OF CONTENTS SECTION I – CHARACTERISTICS PAGE Cartridges and Chambers Full and Abbreviated Names ......................................................................................1 Velocity & Pressure Velocity Data Interpretation .......................................................................................3 Factors Affecting Pressure Measurements..................................................................4 Explanation of Pressure Terminology ........................................................................6 Explanation of Pressure Measuring Systems ..............................................................8 Velocity & Pressure Data – Crusher & Transducer ....................................................9 Bullet Type Abbreviations ........................................................................................22 Primer Primers and Primer Pockets ......................................................................................23 Cartridge and Chamber Drawings 9mm Luger / 9mm Luger +P ....................................................................................24 9x18 Makarov ...........................................................................................................25 9x23 Winchester .......................................................................................................26 10mm Automatic ......................................................................................................27 221 Remington Fireball ............................................................................................28 25 Automatic.............................................................................................................29 30 Luger (7.65mm) ...................................................................................................30 32 Automatic.............................................................................................................31 32 H&R Magnum .....................................................................................................32 32 Smith & Wesson ..................................................................................................33 32 Smith & Wesson Long (32 Colt New Police) ......................................................34 327 Federal Magnum ................................................................................................35 357 Magnum .............................................................................................................36 357 Sig ......................................................................................................................37 38 Automatic.............................................................................................................41 38 Smith & Wesson (38 Colt New Police) ...............................................................38 38 Special / 38 Special +P ........................................................................................39 38 Special Match.......................................................................................................40 38 Super Automatic +P .............................................................................................41 380 Automatic...........................................................................................................42 40 Smith & Wesson ..................................................................................................43 41 Remington Magnum ............................................................................................44 429 Desert Eagle .......................................................................................................45 44 Remington Magnum ............................................................................................46 44 Smith & Wesson Special .....................................................................................47 45 Automatic / 45 Automatic +P ..............................................................................48 45 Automatic Match .................................................................................................49 45 Colt.......................................................................................................................50 45 Glock Automatic Pistol ........................................................................................51 45 Winchester Magnum ............................................................................................52 454 Casull .................................................................................................................53 460 S&W Magnum ...................................................................................................54 475 Linebaugh ..........................................................................................................55 i CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS TABLE OF CONTENTS 480 Ruger ..................................................................................................................56 50 Action Express .....................................................................................................57 500 S&W Magnum ...................................................................................................58 Miscellaneous Frangibility................................................................................................................59 Dummy Cartridge – Gun Functioning ......................................................................60 Dummy Cartridge – Display .....................................................................................61 Blank Cartridge .........................................................................................................62 Tolerance – Bullet Weight ........................................................................................63 SECTION II - PROCEDURES Velocity and Pressure Procedure: Velocity & Pressure Testing ..................................................................64 Velocity & Pressure Barrels: Qualification .............................................................70 Velocity & Pressure Barrels: Mounting in Receivers ..............................................71 Procedure: Use of Piston Hole Gauges ....................................................................72 Procedure: Piezoelectric Transducer Calibration.....................................................73 Transducer Calibration: Increments and Ranges .....................................................76 Transducer Calibration: Equipment Interconnection ...............................................78 Transducer Calibration: Least Square Line Computation .......................................79 Firing Test: Equipment Interconnection ..................................................................81 Reference Ammunition Use ............................................................................................................................83 Secondary Reference Ammunition ...........................................................................85 New Lots ...................................................................................................................86 Identification Protocol ..............................................................................................90 Periodic Assessment .................................................................................................91 Miscellaneous Procedure: Frangibility Testing ...............................................................................95 SECTION III – EQUIPMENT Equipment: Velocity & Pressure Testing .........................................................................96 Copper Crushers Usage of Crusher Cylinders in Pressure Testing ......................................................98 Sample Tarage Table ................................................................................................99 Crusher Cylinders: Dimensions - .146” x .400” ....................................................100 Crusher Cylinders: Dimensions - .225” x .400” ....................................................101 Gas Checks Equipment: .146” and .206” Gas Checks...............................................................102 Equipment: Gas Check Tools – Seating and Knockout .........................................103 Equipment: Gas Check Wax ..................................................................................104 Pistons & Piston Holes Equipment: Pistons and Piston Holes ....................................................................105 Equipment: Piston Hole Gauges ............................................................................108 Piston Oil – Piston and Gas Check .........................................................................110 Headspace Gauges Equipment: Headspace Gauges..............................................................................111 ii CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS TABLE OF CONTENTS Reference Ammunition Equipment: Reference Ammunition Supply ..........................................................116 Equipment: Reference Ammunition Order Procedure ...........................................117 Miscellaneous Equipment: Frangibility Testing ............................................................................118 Supplier Contact Information .................................................................................119 Equipment: Schematic Layout of Velocity Screens ..............................................120 Equipment: Universal Receiver Collar & Test Barrel ...........................................121 Universal Receiver Test Barrel: Installation of Pressure Transducers ..................123 Equipment: Transducer Calibration Fixture Plug with O-ring Seal ......................125 Transducer Location Criteria ..................................................................................126 Equipment: Vented Test Barrel – General .............................................................127 Standard V&P Test Barrels - General Procedures for Dimensioning Chambers ................................................................128 Procedures for Measuring Barrel Length ................................................................129 Standard Velocity and Pressure Test Barrels 9mm Luger / 9mm Luger +P ..................................................................................130 9x18 Makarov .........................................................................................................131 9x23 Winchester .....................................................................................................132 10mm Automatic ....................................................................................................133 221 Remington Fireball ..........................................................................................134 25 Automatic...........................................................................................................135 30 Luger (7.65mm) .................................................................................................136 32 Automatic...........................................................................................................137 32 H&R Magnum ...................................................................................................138 32 Smith & Wesson ................................................................................................139 32 Smith & Wesson Long (32 Colt New Police) ....................................................140 327 Federal Magnum ..............................................................................................141 357 Magnum ...........................................................................................................142 357 Sig ....................................................................................................................143 38 Automatic...........................................................................................................146 38 Smith & Wesson (38 Colt New Police) .............................................................144 38 Special / 38 Special / 38 Special +P..................................................................145 38 Super Automatic +P ...........................................................................................146 380 Automatic.........................................................................................................147 40 Smith & Wesson ................................................................................................148 41 Remington Magnum ..........................................................................................149 429 Desert Eagle .....................................................................................................150 44 Remington Magnum ..........................................................................................151 44 Smith & Wesson Special ...................................................................................152 45 Automatic / 45 Automatic +P / 45 Automatic Match ........................................153 45 Colt.....................................................................................................................154 45 Glock Automatic Pistol ......................................................................................155 45 Winchester Magnum ..........................................................................................156 454 Casull ...............................................................................................................157 460 S&W Magnum .................................................................................................158 475 Linebaugh ........................................................................................................159 480 Ruger ................................................................................................................160 iii CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS TABLE OF CONTENTS 50 Action Express ...................................................................................................161 500 S&W Magnum .................................................................................................162 SECTION IV – DEFINITIVE PROOF LOADS Definition and Purpose ....................................................................................................163 Proof Pressure Data Interpretation ...................................................................................164 Proof Pressure Data – Crusher .........................................................................................166 Proof Pressure Data – Transducer....................................................................................168 Proof Load Supply ...........................................................................................................170 Proof Cartridge Identification ..........................................................................................171 Definitive Proof Package Identification...........................................................................172 iv SECTION I – CHARACTERISTICS CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS CARTRIDGES AND CHAMBERS FULL AND ABBREVIATED NAMES CARTRIDGES AND CHAMBERS FULL AND ABBREVIATED NAMES The following list presents the recommended full names and abbreviated names of the centerfire pistol and revolver cartridges and chambers currently supplied for various types of firearms. These full or abbreviated names should be used on cartridge headstamps and on firearm markings to properly identify the caliber. ORDER OF LISTING Lists of centerfire pistol and revolver cartridges are arranged according to the following rules: 1) All Metric cartridges a) First in ascending numerical order of approximate caliber designation, b) Then in alphabetical order. 2) Followed by US Customary unit cartridges a) First in ascending numerical order of approximate caliber designation, b) Then alphabetical order. 3) Within each of the above groups, cartridges are arranged in order of: a) 2-digit numbers, b) 2-digit numbers and a hyphen followed by more numbers, c) 3-digit numbers. For lists that present both cartridge name and several bullet weights, list in ascending numerical order of bullet weights. Active Cartridges and Chambers Full Name Abbreviated Name 9mm Luger .................................................... 9mm Luger 9mm Luger +P ....................................... 9mm Luger +P * 9x18 Makarov ................................................. 9x18 Mak 9x23 Winchester .............................................. 9x23 Win 10mm Automatic ......................................... 10mm Auto 221 Remington Fireball .......................221 Rem Fireball 25 Automatic.......................................................25 Auto 30 Luger (7.65mm) .......................... 30 Luger (7.65mm) 32 Automatic.......................................................32 Auto 32 H&R Magnum ......................................32 H&R Mag 32 Smith & Wesson .......................................... 32 S&W 32 Smith & Wesson Long ............................... 32 S&WL a.k.a. 32 Colt New Police ................................. 32 CNP * This ammunition is loaded to a higher pressure, as indicated by the +P marking on the case headstamp, to achieve higher velocity. Use only in firearms especially designed for this cartridge and so recommended by the manufacturer. 1 SECTION I – CHARACTERISTICS CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS CARTRIDGES AND CHAMBERS FULL AND ABBREVIATED NAMES 327 Federal Magnum ................................. 327 Fed Mag 357 Magnum ..................................................... 357 Mag 357 Sig ................................................................ 357 Sig 38 Automatic.......................................................38 Auto 38 Smith & Wesson .......................................... 38 S&W a.k.a. 38 Colt New Police ................................. 38 CNP 38 Special .............................................................. 38 Spl 38 Special Match........................................ 38 Spl Match 38 Special +P ................................................. 38 Spl +P * 38 Super Automatic +P ..................... 38 Super Auto +P* 380 Automatic...................................................380 Auto 40 Smith & Wesson .......................................... 40 S&W 41 Remington Magnum .............................. 41 Rem Mag 429 Desert Eagle ................................................. 429 DE 44 Remington Magnum .............................. 44 Rem Mag 44 Smith & Wesson Special ....................... 44 S&W Spl 45 Automatic.......................................................45 Auto 45 Automatic Match ............................... 45 Auto Match 45 Automatic +P .......................................... 45 Auto +P* 45 Colt.................................................................. 45 Colt 45 Glock Automatic Pistol ..................................45 GAP 45 Winchester Magnum .............................. 45 Win Mag 454 Casull ...................................................... 454 Casull 460 S&W Magnum ................................. 460 S&W Mag 475 Linebaugh ........................................ 475 Linebaugh 480 Ruger ........................................................ 480 Ruger 50 Action Express ................................................. 50 AE 500 S&W Magnum ................................. 500 S&W Mag * This ammunition is loaded to a higher pressure, as indicated by the +P marking on the case headstamp, to achieve higher velocity. Use only in firearms especially designed for this cartridge and so recommended by the manufacturer. 2 SECTION I – CHARACTERISTICS CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS VELOCITY DATA INTERPRETATION VELOCITY DATA INTERPRETATION Velocity recommendations are stated on the basis of a nominal lot mean velocity as measured using equipment in accordance with the requirements of Section III and the procedures detailed in Section II. Due to the fact that sporting firearms for general distribution are typically manufactured to dimensional tolerances greater than those specified for test barrels, there should be no expectation that these velocities can be duplicated from any test utilizing firearms. This situation is further confounded by discrepancies in barrel length. Furthermore, once ammunition has left the control of the manufacturer, storage conditions outside those recommended by the manufacturer may cause variations in the velocity as measured using test equipment and procedures which conform to the requirements of this Standard. The values presented on pages 9 through 21 are recommended values for the use of ammunition producers at the time of manufacture. It is the responsibility of the manufacturer to establish sample sizes, sampling frequencies, and tolerances to ensure the performance of the ammunition obtained by the ultimate user meets all applicable safety and functional standards. Of particular importance in establishing velocity tolerances is the understanding that velocities significantly higher than the nominal lot mean can cause actual maximum range performance to exceed expected values. Ammunition tested subsequent to manufacture using equipment and procedures conforming to these guidelines can be expected to produce velocities within a tolerance of ±90 fps of the tabulated values. 3 SECTION I – CHARACTERISTICS CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS FACTORS AFFECTING PRESSURE MEASUREMENTS FACTORS AFFECTING PRESSURE MEASUREMENTS Two principal methods of measuring centerfire pistol and revolver pressures are recognized: the copper crusher method and the piezoelectric transducer method. One or the other may be used or they may be used simultaneously. There are three principal factors affecting pressure measurements. These are instrumentation, ammunition and procedure. The following lists present the items in each category that may cause difficulties in testing carried out with the two methods. I. FACTORS IN COPPER CRUSHER TESTING INSTRUMENTATION 1. Condition of test barrel (whether minimum or maximum bore, chamber size and headspace, amount of erosion at throat and bore). 2. Diameter of piston and piston hole. 3. Fit of piston in piston hole. 4. Location of piston hole. 5. Tightness of barrel mounting in Universal Receiver, if used. 6. Shape, size and protrusion of firing pin beyond breech face. 7. Force of firing pin blow. 8. Size, material and characteristics of the pressure-sensitive element of the gauge (copper crusher cylinders). 9. Type, size and condition of gas check. 10. Type of piston and gas check lubricant. 11. Quality and tolerance of piston hole gauges and headspace gauges. 12. Quality of crusher measuring instrument. AMMUNITION 1. 2. 3. Condition of cartridge. Position of powder in cartridge case. Temperature of ammunition. PROCEDURE 1. 2. 3. 4. 5. 6. 7. 8. Failure to mount pressure barrel properly in Universal Receiver or other test action to assure minimum headspace. Failure to rotate cartridge and close breech carefully to assure proper powder positioning. Failure to wipe piston ends, crusher and setscrew face to remove excess oil. Failure to center crusher cylinder on piston and properly adjust setscrew. Failure to fire warming shots. Overheating barrel by excessive rate of fire. Failure to clean bore and control metal fouling. Failure to clear barrel of brass disk blanked from the case wall and gas check from previous shot. 4 SECTION I – CHARACTERISTICS CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS FACTORS AFFECTING PRESSURE MEASUREMENTS II. FACTORS IN PIEZOELECTRIC TRANSDUCER TESTING INSTRUMENTATION 1. 2. 3. 4. 5. 6. 7. 8. 9. Condition of test barrel (whether minimum or maximum bore, chamber size and headspace, amount of erosion at throat and bore). Fit of transducer in barrel. Location of transducer. Tightness of barrel mounting in Universal Receiver, if used. Shape, size and protrusion of firing pin beyond breech face. Force of firing pin blow. Characteristics of the transducer. Quality of the transducer. Quality of the read-out system. AMMUNITION 1. 2. 3. Condition of cartridge. Position of powder in cartridge case. Temperature of ammunition. PROCEDURE 1. 2. 3. 4. 5. 6. 7. 8. Failure to mount pressure barrel properly in Universal Receiver or other test action to ensure minimum headspace. Failure to rotate cartridge and close breech carefully to assure proper powder positioning. Failure to fire warming shots. Overheating barrel by excessive rate of fire. Failure to clean bore and control metal fouling. Failure to protect transducer against contamination, such as oil or water. Transducer calibration. Read-out system calibration. 5 EXPLANATION OF PRESSURE TERMINOLOGY SECTION I – CHARACTERISTICS CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS EXPLANATION OF PRESSURE TERMINOLOGY The SAAMI Pressure data outlined in this section is based on a Maximum Average Pressure (MAP) for each cartridge and a Coefficient of Variation of 5%. The Coefficient of Variation (CV) of 5% was based on the CV that exists for the 40,000 psi pressure level and is calculated by dividing the population standard deviation (σ = 2,000 psi) by the Maximum Average Pressure (MAP = 40,000 psi) which equals 0.05 (5%). All other pressure terminology is derived directly from these two terms. SAAMI recognizes two pressure-measuring systems. The preferred system is the piezoelectric transducer system with the transducer flush-mounted in the chamber of the test barrel. Pressure developed by the burning propellant exerts force on the transducer through the cartridge case wall causing the transducer to deflect, creating a measurable electric charge. Pressures measured with this system are expressed in units of "pounds per square inch" (abbreviated psi). The second, older system employs a copper crusher cylinder which is compressed by a piston fitted to a piston hole into the chamber of the test barrel. Pressure generated by the burning propellant acts on the base of the piston forcing the piston to move, thereby permanently compressing the copper cylinder. Pressures measured by this system are expressed in "Copper Units of Pressure” (abbreviated as CUP). Throughout the following text the pressure is expressed in terms of "pounds per square inch" (psi) however, it should be understood that the same procedures apply to pressures expressed in "Copper Units of Pressure" (CUP). Maximum Average Pressure - is the recommended maximum pressure level for loading commercial sporting ammunition. Standard Deviation (σ) - The Standard Deviation for each Maximum Average Pressure level is based on a Coefficient of Variation of 5%. This 5% Coefficient of Variation is maintained throughout the SAAMI pressure spectrum providing a realistic Standard Deviation for each pressure level. To obtain the Standard Deviation for a particular MAP, multiply the MAP by 0.05 (i.e., 40,000 psi x 0.05 = 2,000 psi). Standard Error (σ x ) - The standard error is calculated by dividing the Standard Deviation (population S. D. = σ) by the square root of the sample size σ x = σ n Maximum Probable Lot Mean (MPLM) - The MPLM is calculated by adding two standard errors to the Maximum Average Pressure in order to assure there is a 97.5% probability that the Maximum Probable Lot Mean pressure is not exceeded. See Figure 1. 6 EXPLANATION OF PRESSURE TERMINOLOGY SECTION I – CHARACTERISTICS CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS The SAAMI pressures are calculated based on a sample size of ten (10). The Maximum Probable Lot Mean represents the midpoint of the upper service pressure distribution. See Figure 1. For example, if the Maximum Average Pressure is 40,000 psi, the Maximum Probable Lot Mean (MPLM) is calculated as follows: MPLM = Maximum Average Pressure + 2 standard errors MPLM = 40,000 psi + [(40,000 psi x 0.05)/√10] x 2 MPLM = 40,000 psi + (633 psi x 2) = 40,000 + 1266 psi = 41,266 psi rounded to 41,300 psi Maximum Probable Sample Mean (MPSM) - is the maximum expected average pressure that may be observed in the testing of product subsequent to its manufacture and is not intended for use as a loading control point. The Maximum Probable Sample Mean is positioned three (3) standard errors above the Maximum Probable Lot Mean i.e., MPLM + 3 σ x . See Figure 1. The Maximum Probable Sample Mean defined here is the value previously referred to in the ANSI/SAAMI Standards as the Maximum Product Average. 2 Standard errors MAP 40,000 3 Standard errors MPLM 41,300 MPSM 43,200 Pressure, psi Figure 1 Maximum Extreme Variation - The maximum allowable sample E.V. (Extreme Variation or Range) is a statistic derived from the knowledge of the population Standard Deviation. Applying table figures from the Relative Range Tables (Biometrika Tables for Statisticians) we calculate the Maximum E.V. or Range as (population σ) x 5.16 (table constant for sample of 10 at 99.0% confidence level) i.e., 2,000 psi x 5.16 = 10,320 psi rounded down to 10,300 psi. 7 SECTION I – CHARACTERISTICS CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS EXPLANATION OF PRESSURE MEASURING SYSTEMS EXPLANATION OF PRESSURE MEASURING SYSTEMS The two SAAMI recognized pressure-measuring systems for centerfire pistol and revolver cartridges are the copper crusher system and the piezoelectric transducer system. A brief explanation of these two systems follows: COPPER CRUSHER SYSTEM This system employs a copper crusher cylinder that is compressed by a piston fitted to a piston hole into the chamber of the test barrel. The pressure developed by the gases from the burning propellant acts through the piston hole, allowing the gases to force the piston upward, and thereby permanently compressing the copper crusher cylinder. The Sporting Arms and Ammunition Manufacturers' Institute has adopted the pressure units designation of "Copper Units of Pressure" (abbreviated CUP) for this system. This designation applies only to values obtained using the particular crushers, tarage tables and methods outlined in this Standard. PIEZOELECTRIC TRANSDUCER SYSTEM This system employs a piezoelectric transducer flush mounted in the chamber of the test barrel. Pressure developed by the gases from the burning propellant exerts force on the transducer through the cartridge case wall causing the transducer to deflect, creating a measurable electric charge. This electrical charge is converted into a reading of pressure. The Sporting Arms and Ammunition Manufacturers' Institute has adopted the pressure units designation of "pounds per square inch" (abbreviated psi) for this system. This designation applies to values obtained with transducers and methods as outlined in this Standard. 8 VELOCITY AND PRESSURE DATA – CRUSHER & TRANSDUCER SECTION I – CHARACTERISTICS CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS VELOCITY AND PRESSURE: VELOCITY & PRESSURE DATA (Cont’d) (N/E = Not Established) Cartridge Bullet Weight (gr.) 88 95 100 105 115 9mm Luger 124 135 147 150 90 101 9mm Luger +P 115 124 135 (1) Based on sample size η=10. Velocity, fps Nominal Mean Nominal Mean Instrumental Instrumental @ 15’ @ 15’ Vented Bbl.(2) Test Bbl. (3) 1,500 1,330 1,110 1,195 1,200 1,135 1,210 1,030 1,090 1,130 1,170 1,010 1,060 985 900 (3) 1,375 1,225 1,100 1,235 1,180 1,090 CRUSHER Pressure, CUP/100(1) Maximum Maximum Maximum Average Probable Probable Pressure Lot Mean Sample Mean (MAP) (MPLM) (MPSM) TRANSDUCER Pressure psi/100(1) Maximum Maximum Maximum Average Probable Probable Pressure Lot Mean Sample Mean (MAP) (MPLM) (MPSM) 330 340 356 350 361 378 N/E N/E N/E 385 397 415 (2) Vented barrel velocities are provided for information only. Vented test barrels are used for the establishment of catalog velocity values for cartridges normally chambered in revolvers. 9 (3) Revolvers not normally chambered for this cartridge. VELOCITY AND PRESSURE DATA – CRUSHER & TRANSDUCER SECTION I – CHARACTERISTICS CENTERFIRE PISTOL & REVOLVER SAAMI VOLUNTARY PERFORMANCE STANDARDS VELOCITY AND PRESSURE: