The answer is not clear cut. Primers are made from chemicals. The activation energy varies. Some primers, within the same lot, are more sensitive than others. Its going to follow a statistical curve, but I don't know the distribution. Maybe somthing similiar to a upside down bath tub curve.
The book "Ammunition Making" by George Frost has a section on primer testing. (Incidentally now that these books are $115.00 used, I can't find mine
) Primers are tested for lot sensitivity by dropping steel balls on them.
Winchester was helpful in reading to me the industry specification requirement for primer sensitivity for the 308- 30-06 cartridges. Unfortunately Winchester was unable to tell me what the specification number was, just to contact SAMMI to get the specification. Industry organizations do not release their specifications for free, and so I remain ignorant of the spec. And since the following is per a telephone conversation, there may be errors in the transcription:
Code:
Drop Height of 4 oz ball
no misfire no explosion no failure to fire no failure to fire
Any case 100 cases 200 cases all cases
308 Primed case 3” 4.5” 22” 25”
30-06 primed case 3” 4.5” 22” 25”
Mil-P-46610E “Primers, Percussion for Small Arms Ammunition” was the actual military specification for primers. Was until the Clinton/Gore administration “retired” all military specifications. Without creating alternatives. But that is another story. The following section is from Mil-P-46610E:
Code:
3.2 Sensitivity.-The sensitivity shall fall within the limits specified as follows for each type of primer:
Primer Required Case Height in Inches
H +5S H -2S
Dwg . No. B10522621 7.62mm Match 15 3
Dwg . No. B10535489 7.62mm Match 16 3
Dwg , No. B10522621 7.62mm 15 3
Dwg . No. B8594094 7.62mm Match 16 3
Dwg. No. B10522621 7.62mn Grenade 15 3
Dwg . No. B10522621 7.62mm Blank 15 3
Dwg . No. B10535489 7.62mm Blank -Caliber 16 ½ 2½
Dwg . No. B10522621 .30 15 3
Dwg. No. B10535489 Caliber .30 15 2½
Dug. No. A5000131 Caliber .30 15 2½
Dug. No. B8595819 Caliber .30 Match 15 2½
Dwg, No. B10535489 Caliber .30 Match 15 2½
Dwg. No. C7645332 Caliber .30 Blank 15 2½
Dwg. No. B8594094 Caliber .30 Blank 15 2½
Dwg. No. B6200959 Caliber .30 Carbine 18 2½
Dwg. No. C11751131 Caliber .30 Carbine 18 2½
Dwg. No. B7645336 Caliber .45 16 2½
Dwg. No, A5001168 Caliber .45 16 2½
Dwg. No. B7645339 Caliber .50 15 2½
Dwg. No. A5033178 Caliber .50 15 2½
Dwg. NO. B7645336 Caliber .45 Blank 18 3
Dwg. No. A5001168 Caliber .45 Blank 18 3
4.4 Test methods and procedures.
4.4.1 Sensitivity test.-Ambient temperature - The primer shall be inserted into the primer pocket of the cartridge case so that the surface of the primer cup, when measured from the center of the primer, is within the tolerance specified on the applicable cartridge drawing. The test shall be performed in accordance with the complete run-down method described in TECP 700-700, Vol. III: AMCR 715-505, Volumes 3 and 5; or AMSMU-P-715-501FAI as applicable.
4.4.1.1 Two-height method.-The two-height method of testing for sensitivity may be used in lieu of the complete run-down test when sensitivity results for five consecutive lots have been found to comply with the requirements of 3.2 and computed skewness values have been found to be no greater than .787 nor less than -.787 (see 603). However, one out of every 10 lots submitted shall be tested by the complete run-down method. Failure in any test to meet sensitivity or skewness requirements shall be considered sufficient cause to revert to use of the run-down method on each lot. The two-height test shall be conducted in accordance with the two-height method described in AMSMU-P-715-501FA1 Fifty primers shall be tested at each height.
As to calculating firing pin energy, Volume one of "The Bolt Action" by Stuart Ottenson has an appendix.