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Velocity question?s
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<blockquote data-quote="diriel" data-source="post: 527016" data-attributes="member: 26983"><p>This is the information straight from the Neco.navy.mil PDF document:</p><p></p><p><a href="https://www.neco.navy.mil/upload/N00164/N0016409RJN30000209RJN30_0002_att.pdf" target="_blank">https://www.neco.navy.mil/upload/N00164/N0016409RJN30000209RJN30_0002_att.pdf</a></p><p></p><p>"" 3.</p><p>REQUIREMENTS</p><p>3.1 Classification of characteristics. Where critical or major</p><p>characteristic requirements are listed in this specification, they</p><p>are annotated by a "C" or "M" and sequential reference number</p><p>starting with "1" for critical and "101" for major. The letter and</p><p>number are contained in parentheses. The main verbiage of the</p><p>requirement is then surrounded by brackets, "[ ]". Minor</p><p>characteristic requirements contain no annotation. Reference DOD-</p><p>STD-2101.</p><p>3.1.1 Critical characteristic. One that analysis indicates is</p><p>likely, if defective, to create or increase a hazard to human</p><p>safety or to result in failure of a weapon system or major system</p><p>to perform a required mission.</p><p>3.1.2 Major characteristic. One that analysis indicates is not</p><p>critical but is likely, if defective, to result in failure of an</p><p>end item to perform a required mission.</p><p>3.1.3 Minor characteristic. One that analysis indicates is</p><p>significant to product quality but is not likely, if defective, to</p><p>impair the mission performance of the item.</p><p>3.2 First Article. When specified in the solicitation (see 6.2g),</p><p>a sample shall be subjected to First Article inspection in</p><p>accordance with 4.2.</p><p>3.3 Government-loaned property. Government-loaned property (see</p><p>6.2e and 6.4) might be used for performing tests as specified in</p><p>Section 4 and Appendices A, B and C of this specification.</p><p>Government-loaned property shall be described in the contract where</p><p>applicable.</p><p>3.4 Components. MK 248 MOD 1 cartridge components are the</p><p>projectile, the cartridge case, the propellant, and the primer.</p><p>3.4.1</p><p>Projectile.</p><p>The projectile for the MK 248 MOD 1 shall be</p><p>4</p><p>DS/JXNN/C08/1604A</p><p>the 220 grain Sierra MatchKing® Hollow Point Boat Tail (HPBT)</p><p>bullet, commercial part number 2240, manufactured by Sierra</p><p>Bullets, (Drawing 53711-8330251). The bullet shall have a lead or</p><p>lead alloy core and copper or copper alloy jacket. The bullet</p><p>shall have a nominal weight of 220 grains, with a tolerance of ±0.5</p><p>grains. The bullet diameter shall be 0.3086-0.0005 inches. The</p><p>bullet shall be of the reverse drawn, Open Tip Match (OTM) type</p><p>capable of meeting the accuracy requirements as specified in</p><p>paragraph 3.6.4.</p><p>3.4.2 Cartridge case. The cartridge case shall be .300 Winchester</p><p>Magnum constructed of copper alloy in accordance with ASTM B19, and</p><p>shall not be plated. The cartridge case shall meet the external</p><p>dimensional requirements of ANSI/SAAMI Z299.4-1992. (C1) [A vent</p><p>hole shall be present in the primer pocket of the cartridge case].</p><p>3.4.2.1 Headstamp. The cartridge case headstamp marking shall</p><p>consist of the identification code of the manufacturer, last 2</p><p>digits of year of manufacture and the notation "300 WM" or "300 WIN</p><p>MAG" in accordance with drawing 53711-8330252.</p><p>3.4.3 Primer. The primer shall be a large match rifle primer,</p><p>non-corrosive, nickel-plated, boxer type, and shall be of lead-</p><p>styphnate type. The primer shall have a brass anvil and brass cup.</p><p>The primer shall be capable of meeting the ballistic requirements</p><p>herein.</p><p>3.4.4 Propellant. (C2) [Each cartridge shall contain Hodgdon</p><p>H1000 propellant.] The propellant loaded in this cartridge shall</p><p>contain flash reduction additives or coatings, and shall meet the</p><p>temperature stability and ballistic requirements detailed in</p><p>Section 3.6.</p><p>3.5</p><p>Complete cartridge.</p><p>3.5.1 Cartridge assembly. The cartridge assembly shall be</p><p>manufactured and inspected in accordance with drawing 53711-</p><p>8330252.</p><p>3.5.2 Primer seating depth. The primer shall be seated in the</p><p>cartridge case to a depth of (M101) [0.000 to 0.008 inch below the</p><p>face of the cartridge case head.] The primer shall not be staked</p><p>or crimped in place.</p><p>3.5.3 Cartridge overall length. (M102) [The nominal overall</p><p>length of the assembled cartridge shall be 3.500 inches maximum,</p><p>3.450 inches minimum] in accordance with drawing 53711-8330252.</p><p>The distance from the cartridge case head to the 0.300 inch</p><p>diameter datum on the projectile ogive shall be controlled to</p><p>within ± 0.010 inches. The nominal overall length and the distance</p><p>5</p><p>DS/JXNN/C08/1604A</p><p>from the cartridge case head to the 0.300 inch diameter datum on</p><p>the projectile ogive of the assembled cartridge shall be</p><p>established, within the above limits, by the manufacturer to meet</p><p>performance requirements.</p><p>3.5.4 Cartridge headspace. (M103) [The cartridge headspace shall</p><p>be 0.212 inches minimum, 0.220 inches maximum], in accordance with</p><p>drawing 53711-8330252. Cartridge headspace shall be measured from</p><p>the base of the cartridge case to the opposite surface of the belt</p><p>of the cartridge case.</p><p>3.5.5 Primed case sensitivity. Primed Case Sensitivity tests</p><p>shall be conducted on empty primed cases in accordance with 4.5.5.</p><p>Primed case sensitivity shall be as follows:</p><p>a. b. </p><p>3.6</p><p>(C3) [The mean critical height minus two standard</p><p>deviations ( H -2σ) shall be 3.0 inches minimum.]</p><p>(M104) [The mean critical height plus four standard</p><p>deviations ( H +4σ) shall be 22.0 inches maximum.]</p><p>Cartridge ballistic performance.</p><p>3.6.1 Velocity. (M105) [The corrected average muzzle velocity of</p><p>the cartridges conditioned at 70° ± 5° Fahrenheit (F) shall be</p><p>2,850 ± 50 ft/sec. feet per second (fps)]. The standard deviation</p><p>of the corrected muzzle velocity at 70° ± 5° F shall not exceed 15</p><p>fps. This test shall be conducted in accordance with paragraph</p><p>4.5.6.</p><p>3.6.2 Chamber Pressure. (M106) [The corrected average chamber</p><p>pressure shall not exceed 68,100 pounds per square inch (psi) at</p><p>70°F.] Neither the chamber pressure of an individual sample test</p><p>cartridge nor the average chamber pressure plus three standard</p><p>deviations of chamber pressure shall exceed 78,900 psi. This test</p><p>shall be conducted in accordance with paragraph 4.5.7.</p><p>3.6.3 Operational Temperature Stability (High and Low). The</p><p>velocity and pressure of sample cartridges conditioned and fired at</p><p>the temperature extremes specified below shall be in accordance</p><p>with 3.6.3.1 and 3.6.3.2.</p><p>a. Conditioned at 165°F - 5°F for not less than 2 hours</p><p>immediately prior to firing.</p><p>b. Conditioned at -20°F + 5°F for not less than 2 hours</p><p>immediately prior to firing.</p><p>6</p><p>DS/JXNN/C08/1604A</p><p>3.6.3.1 Velocity. (M107) [The average corrected muzzle velocity</p><p>of the sample cartridges conditioned at -20°F shall not vary by</p><p>more than 75 fps from the average corrected muzzle velocity of the</p><p>sample cartridges conditioned at 165°F.]</p><p>3.6.3.2 Chamber Pressure. (M108) [The average corrected chamber</p><p>pressure of the sample cartridges conditioned at -20°F and 165°F</p><p>shall not exceed 71,500 psi.] Neither the chamber pressure of an</p><p>individual sample test cartridge nor the average chamber pressure</p><p>plus three standard deviations of chamber pressure shall exceed</p><p>78,900 psi.</p><p>3.6.4</p><p>Accuracy.</p><p>3.6.4.1 300 yard accuracy. (M109) [The extreme spread of any</p><p>individual 10-shot group shall not exceed 4.5 inches at 300 yards.</p><p>The average extreme spread of ten, 10-shot groups shall not exceed</p><p>3.5 inches at 300 yards.]</p><p>3.6.4.2 600 yard accuracy. (M110) [The extreme spread of any</p><p>individual 10-shot group shall not exceed 9.0 inches at 600 yards.</p><p>The average extreme spread of ten, 10-shot groups shall not exceed</p><p>7.0 inches at 600 yards.] This test shall be conducted in</p><p>accordance with 4.5.8 and Appendix B, except that the range to</p><p>target shall be 600 + 1 yard. This test shall be conducted as part</p><p>of the First Article Sample or if a First Article Sample is not</p><p>part of the contract, as part of the first production lot of a new</p><p>contract.</p><p>3.6.5 Function and Casualty. (M111) [There shall be no weapon</p><p>stoppages due to the cartridge.] The cartridge shall meet all</p><p>function and safety requirements of Table I. Misfires shall be</p><p>considered separately in accordance with Table I. Function and</p><p>causality testing shall be conducted using the rifles as specified</p><p>in the contract.</p><p>""</p><p></p><p>Please read and note that 68K psi +- a good bit is what they are running and their COAL is like 3.5".... it is all there... read and enjoy. </p><p></p><p></p><p>Have fun,</p><p>Gary</p></blockquote><p></p>
[QUOTE="diriel, post: 527016, member: 26983"] This is the information straight from the Neco.navy.mil PDF document: [url]https://www.neco.navy.mil/upload/N00164/N0016409RJN30000209RJN30_0002_att.pdf[/url] "" 3. REQUIREMENTS 3.1 Classification of characteristics. Where critical or major characteristic requirements are listed in this specification, they are annotated by a “C” or “M” and sequential reference number starting with “1” for critical and “101” for major. The letter and number are contained in parentheses. The main verbiage of the requirement is then surrounded by brackets, “[ ]”. Minor characteristic requirements contain no annotation. Reference DOD- STD-2101. 3.1.1 Critical characteristic. One that analysis indicates is likely, if defective, to create or increase a hazard to human safety or to result in failure of a weapon system or major system to perform a required mission. 3.1.2 Major characteristic. One that analysis indicates is not critical but is likely, if defective, to result in failure of an end item to perform a required mission. 3.1.3 Minor characteristic. One that analysis indicates is significant to product quality but is not likely, if defective, to impair the mission performance of the item. 3.2 First Article. When specified in the solicitation (see 6.2g), a sample shall be subjected to First Article inspection in accordance with 4.2. 3.3 Government-loaned property. Government-loaned property (see 6.2e and 6.4) might be used for performing tests as specified in Section 4 and Appendices A, B and C of this specification. Government-loaned property shall be described in the contract where applicable. 3.4 Components. MK 248 MOD 1 cartridge components are the projectile, the cartridge case, the propellant, and the primer. 3.4.1 Projectile. The projectile for the MK 248 MOD 1 shall be 4 DS/JXNN/C08/1604A the 220 grain Sierra MatchKing® Hollow Point Boat Tail (HPBT) bullet, commercial part number 2240, manufactured by Sierra Bullets, (Drawing 53711-8330251). The bullet shall have a lead or lead alloy core and copper or copper alloy jacket. The bullet shall have a nominal weight of 220 grains, with a tolerance of ±0.5 grains. The bullet diameter shall be 0.3086-0.0005 inches. The bullet shall be of the reverse drawn, Open Tip Match (OTM) type capable of meeting the accuracy requirements as specified in paragraph 3.6.4. 3.4.2 Cartridge case. The cartridge case shall be .300 Winchester Magnum constructed of copper alloy in accordance with ASTM B19, and shall not be plated. The cartridge case shall meet the external dimensional requirements of ANSI/SAAMI Z299.4-1992. (C1) [A vent hole shall be present in the primer pocket of the cartridge case]. 3.4.2.1 Headstamp. The cartridge case headstamp marking shall consist of the identification code of the manufacturer, last 2 digits of year of manufacture and the notation “300 WM” or “300 WIN MAG” in accordance with drawing 53711-8330252. 3.4.3 Primer. The primer shall be a large match rifle primer, non-corrosive, nickel-plated, boxer type, and shall be of lead- styphnate type. The primer shall have a brass anvil and brass cup. The primer shall be capable of meeting the ballistic requirements herein. 3.4.4 Propellant. (C2) [Each cartridge shall contain Hodgdon H1000 propellant.] The propellant loaded in this cartridge shall contain flash reduction additives or coatings, and shall meet the temperature stability and ballistic requirements detailed in Section 3.6. 3.5 Complete cartridge. 3.5.1 Cartridge assembly. The cartridge assembly shall be manufactured and inspected in accordance with drawing 53711- 8330252. 3.5.2 Primer seating depth. The primer shall be seated in the cartridge case to a depth of (M101) [0.000 to 0.008 inch below the face of the cartridge case head.] The primer shall not be staked or crimped in place. 3.5.3 Cartridge overall length. (M102) [The nominal overall length of the assembled cartridge shall be 3.500 inches maximum, 3.450 inches minimum] in accordance with drawing 53711-8330252. The distance from the cartridge case head to the 0.300 inch diameter datum on the projectile ogive shall be controlled to within ± 0.010 inches. The nominal overall length and the distance 5 DS/JXNN/C08/1604A from the cartridge case head to the 0.300 inch diameter datum on the projectile ogive of the assembled cartridge shall be established, within the above limits, by the manufacturer to meet performance requirements. 3.5.4 Cartridge headspace. (M103) [The cartridge headspace shall be 0.212 inches minimum, 0.220 inches maximum], in accordance with drawing 53711-8330252. Cartridge headspace shall be measured from the base of the cartridge case to the opposite surface of the belt of the cartridge case. 3.5.5 Primed case sensitivity. Primed Case Sensitivity tests shall be conducted on empty primed cases in accordance with 4.5.5. Primed case sensitivity shall be as follows: a. b. 3.6 (C3) [The mean critical height minus two standard deviations ( H -2σ) shall be 3.0 inches minimum.] (M104) [The mean critical height plus four standard deviations ( H +4σ) shall be 22.0 inches maximum.] Cartridge ballistic performance. 3.6.1 Velocity. (M105) [The corrected average muzzle velocity of the cartridges conditioned at 70° ± 5° Fahrenheit (F) shall be 2,850 ± 50 ft/sec. feet per second (fps)]. The standard deviation of the corrected muzzle velocity at 70° ± 5° F shall not exceed 15 fps. This test shall be conducted in accordance with paragraph 4.5.6. 3.6.2 Chamber Pressure. (M106) [The corrected average chamber pressure shall not exceed 68,100 pounds per square inch (psi) at 70°F.] Neither the chamber pressure of an individual sample test cartridge nor the average chamber pressure plus three standard deviations of chamber pressure shall exceed 78,900 psi. This test shall be conducted in accordance with paragraph 4.5.7. 3.6.3 Operational Temperature Stability (High and Low). The velocity and pressure of sample cartridges conditioned and fired at the temperature extremes specified below shall be in accordance with 3.6.3.1 and 3.6.3.2. a. Conditioned at 165°F - 5°F for not less than 2 hours immediately prior to firing. b. Conditioned at -20°F + 5°F for not less than 2 hours immediately prior to firing. 6 DS/JXNN/C08/1604A 3.6.3.1 Velocity. (M107) [The average corrected muzzle velocity of the sample cartridges conditioned at -20°F shall not vary by more than 75 fps from the average corrected muzzle velocity of the sample cartridges conditioned at 165°F.] 3.6.3.2 Chamber Pressure. (M108) [The average corrected chamber pressure of the sample cartridges conditioned at -20°F and 165°F shall not exceed 71,500 psi.] Neither the chamber pressure of an individual sample test cartridge nor the average chamber pressure plus three standard deviations of chamber pressure shall exceed 78,900 psi. 3.6.4 Accuracy. 3.6.4.1 300 yard accuracy. (M109) [The extreme spread of any individual 10-shot group shall not exceed 4.5 inches at 300 yards. The average extreme spread of ten, 10-shot groups shall not exceed 3.5 inches at 300 yards.] 3.6.4.2 600 yard accuracy. (M110) [The extreme spread of any individual 10-shot group shall not exceed 9.0 inches at 600 yards. The average extreme spread of ten, 10-shot groups shall not exceed 7.0 inches at 600 yards.] This test shall be conducted in accordance with 4.5.8 and Appendix B, except that the range to target shall be 600 + 1 yard. This test shall be conducted as part of the First Article Sample or if a First Article Sample is not part of the contract, as part of the first production lot of a new contract. 3.6.5 Function and Casualty. (M111) [There shall be no weapon stoppages due to the cartridge.] The cartridge shall meet all function and safety requirements of Table I. Misfires shall be considered separately in accordance with Table I. Function and causality testing shall be conducted using the rifles as specified in the contract. "" Please read and note that 68K psi +- a good bit is what they are running and their COAL is like 3.5".... it is all there... read and enjoy. Have fun, Gary [/QUOTE]
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